In the early history of the small town of "Terrasini" there are some elusive facts which still have not been discovered, among which is the true meaning of “Terrasini.”
The foundation of Terrasini
Historically Terrasini (inhabited mostly by peasant families) arose in the 17th century after a union with Favarotta (a fishermens village). The name ‘Favarotta’ is derived from 'fawar', the Arabic for 'fountain'; it refers to a spring of cool water that gushes up from slabs of rose shale where Our Lady of Providence surveys the tuna fleet .
Terrasini was ruled by the "milites" Abbate from 1282, with Palmerio Abate, Baron of Carini and the island of Favignana, who organized the Sicilian rebellion against Charles of Anjou in 1282 with the "Sicilian Vespers" .
At the end of the 14th century Ubertino La Grua (died 1408) had the 'investiture of the barony of Carini in 1397, then the La Grua in 1593 also sold the manor of Terrasini . Fazio di Fazio and his wife Violante gave the fiefdom of Cinisi (which then bordered on the feud of Terrasini and extended from Carini as far as the sea) to the Gregorian Monastery of "San Martino delle Scale." .
So the feud was still held by the family of La Grua (16th century), who also built the church in the village of Terrasini. Afterwards the feud of Terrasini passed to Donato Gazzara (1664).
Terrasini in recent centuries
In the early 17th century the two villages were separated by a valley where the Gifina river flowed, now disappeared after being covered with earth, and in 1836 a Bourbon edict united them as a single county .
After the abolition of feudalism in 1812 Terrasini had a boost thanks to wine-related activities in the name of Henri d'Orleans Duc d'Aumale (1822-1897). In 1878 he owned a winery and olive oil with warehouses in Terrasini . In fact the Duke of Aumale bought the former fiefdom 'Zucco' in 1853, and he began to vinify in 1860. At his factory in Terrasini he had thousands of barrels where he aged the white and red old wine called "Zucco".
In modern times Terrasini has been basically devoted to tuna fishing and agriculture. These activities are still very important in Terrasini, but we must add tourism to them, which in recent years has brought Terrasini to be a remarkable seaside resort, thanks also to the cultural heritage of the town.
Of interest to history enthusiasts, in the late 1960s an important wreck of the first century AD with a cargo of Spanish amphorae was discovered in Terrasini, and a part of these finds are now preserved in the “Antiquarium”, built for this purpose.
Origins of the name Terrasini
Almost all scholars (with some exceptions) seem to agree with V. Amico, according to whom:
"[...] the name of Terrasini probably derives from the nearby promontory called 'Rama', that formed (with the opposite Cape San Vito) the Gulf of ‘Castellammare’, which is the ancient ‘Sinus Aegestanus’. Therefore, the village began to be called "Terra Sinus", in some covenants by the nearby gulf, then vulgarly "Terrasini," and now "Terrasini-Favarotta" because Terrasini merged in 1836 for the Sovereign Order with this village, which previously belonged to the municipality of Cinisi [...]" .
Therefore, the etymology of "Terrasini" would be "Terra Sinus" or "Inlet [of the earth]", "Gulf". This would seem also in perfect harmony with the geographical position of the town. However, Professor Purpura clarified that:
"[...] the popular explanation, accepted by Amico (...) about the name 'Terrasini' as "inlet of the earth" appears questionable. In fact, we observe that in this case many places should be called 'Terrasini' but this designation, however, seems to be unique in Italy […]” .
First we point out that, even before a village called "Terrasini" was founded in the 17th century this territory was called "Tirrasinum", "Terrasinis", "Tirrasinis" “Terrasini” around the 13th and 14th century, and as noted by G. Purpura:
"[...] In medieval documents in 1350 and 1390, the term 'Terrasini' appears as the name of a feud (...) The Abate family owned Terrasini in 1350 (...) Ubertino La Grua was baron of Carini and of the Terrasini manor in c.1390. The feud of Terrasini was also a domain of the monastery of ‘San Martino delle Scale’ [...]." .
In ancient times, there probably was a place called "Cetaria", or the "place where they used to catch tuna", the "fishing net", mentioned by Cicero (106-43 BC) and Pliny (23-79 AD). During the Arab period this place was called "Sâqiât Gins" (the "bindolo" of “Cinisi” [The "Bindolo" was a water-wheel equipped with small buckets to draw water and irrigate the fields]), in the sense of "tank" and “watering place”, probably “a farming implement installed to irrigate the fields”, or a "trough" .
The earliest documents attested without a doubt that the feud of Terrasini belonged to the Abate family. In the Index by Antonino Marrone  we read that the Abate were “milites”, or “knights”, “barons”; and around 1309:
"[...] The 'dominus miles' Nicola (I) Abate married Philippa from Palermo, cousin of Matteo Sclafani … (1309) [...]."
Additionally, Nicola Abate granted to the brothers Perrello:
"[...] two plots of land, of which one is called "Casale calidum” [Hot Hamlet] and another “Tirrasinum” [Terrasini], located in the territory of Carini and Cinnisi, close to the properties of the heir of Matteo Pipitone. Around 1309 there was a "tenimentum" called “Tirrasinum”, where it is easy to see the current Terrasini. Furthermore, the term recurs in a form very close to two other contemporary documents relating to the estates of the Abate in 1335: […]" .
A family member of the Abate was also the baron of Favarotta:
"[...] Riccardo Abate in 1346 is baron of 'Favarotta' in the territory of Cefalà contracted out to Bindo di Ser Lombardo (Asp., SN, 10N, 58), and of the castle and the estate of Cefalà in 1349 [...]” .
So we know that Terrasini originally appears as a feud belonging to the Abate family. The Abate were classified as "milites", a term which, in the feudal language of the time, was virtually synonymous with "Baron", and perhaps this remark can be usable for the "elusive" etymology of Terrasini. At this point we put in a good word for the ancient and traditional etymology proposed by Vito Amico, who derives Terrasini from “Terra Sinus” or “Terrae sinus” (inlet of the earth).
The Normans did not have a specific term for the word "baron", and in the Royal Chancellery the Latin word "miles" was normally used; but in some ancient parchments the Greek term "terréres” was also used. With regard to this word, Professor Vera Von Falkenhausen wrote that
"[...] The beneficiary of an estate could be the 'baro' [baron] or 'miles'. The word 'baro' was unknown before the arrival of the Normans in southern Italy (...) Another term with the same meaning as Baron is the Greek word ‘terrérios’, '’terréres’, or ‘at-tarariya’ [in Arabic], which is found only in some Arab and Greek parchments (...)
Probably the Greek ‘terrérios’ is not derived from the Latin 'terrarius' but from the French 'terrier', that with the meaning of ‘seigneur terrier et justicier’ is quite common in the medieval French language (...) It is a term that did not really enter the vocabulary of Greek and Arabic in Southern Italy or Sicily, but it is a Chancellery jargon to indicate the Norman concept of ‘baron’ [...]" .
V. Von Falkenhausen remarked that the "Baron" of Caltavuturo was called "Terréres tes Xòras" , or "Baron of the territory." Assuming that the chancellery terminology had been applied to the Latin expression "Terra sinus" (hence "Terrasini," according to V. Amico), ther would emerge in Greek "terrères tou sinou" (where "sinou" is the genitive of "sinos" = Latin "sinus" [creek, gulf], and with the loss of "tou" would appear "terréres-sinos", "terrérios-sinos" "[= Lord-Baron of the Gulf. ]
From “terrérios-sinos” it is very easy to get to the Latin “terra sinus”, and finally to arrive at a vernacular terminology such as "terra", "tirra" and similar terms, from which 'Tirra-sinum', "Terra-sinis", "Tirra-sinis", "Terra-sini” (the actual name).
In conclusion, the term "Terrasini" would indicate (perhaps!) simply the "status" of the "Baron's land area” of the gulf, as if we said the "Bay or Valley of the Baron," "creek belonging to the Baron."
The double check that things could have been so is the legal formula in the document where "Nicolaus Abbas" was defined as "miles pro Asinello, Chifala, Carmorochis ...", or “Baron of (“pro”= of) Asinello, (...)". If the formula had been in Greek, it would have been like this: “Nicolaus Abbas 'terréres tou' Asinello, Chifala ...", which means “Baron of Asinello, Chifala ...".
Moving from theory to an indisputable historical fact, the habit of translating "terrérion" with "Baron" or of translating some chancellery expressions from Greek into Latin, is also attested:
"in a Greek privilege of Roger I (1031-1101) in favor of the church of Messina ... [where] the Greek expression “iereis ton emon ‘terrerion’” is translated into Latin as ‘sacerdotes Meorum Baronum’ [The priests of my Barons]" .
The Arabs translated "terréres" with “at-tarariya”. The name of "Terrasini" constitutes a "unicum" (Purpura, p. 59), and presumably this was due to the fact that the term "terréres," as Professor Von Falkenhausen noted, was used only in a few Norman and Arab parchments, and that it had a very limited circulation.
The assumption proposed above is also corroborated by the fact that, historically, the whole area of Terrasini belonged to the most powerful baronies strongly linked to the Normans; for example, the area of Carini, in which were also included Favarotta and Terrasini, when under the dominion of the Normans was owned by Rodolfo Bonello, Baron of Apulia. As Michele Amari wrote:
“the Bonello were the comrades-in-arms of Roger I, and they do not seem neither French, nor Lombards and nor Greek, but they would appear instead to be of Italic Sicilian family” 
See the travel guide for Terrasini.
1. See V. Amico, “Dizionario topografico della Sicilia” ["Topographical Dictionary of Sicily”], Palermo, 1856, Vol. II: 393
2. See G. Purpura, “Il relitto di Terrasini”, in “Sicilia Archeologica”, 1974, nn. 24-25, p. 59 nota 23
3. ref 2, See p. 59 and note 27
4. ref 2, See Purpura, p. 59
5. “Repertorio della feudalità siciliana”, Palermo, Mediterranea, 2006: 17 ff.
6. ref 5, See pp. 17-19
7. See A. Marrone, “Repertorio”, p. 19 nota 6
8. See F. Viviano, “Blood washes blood”, Century, 2001, p. 12
9. with regard to the Bourbon decree, See “Collezione delle Leggi e de' decreti reali del Regno delle Due Sicilie” [" The Collection of Laws and of royal decrees of the Kingdom of the Two Sicilies], Naples, 1836: 85: “[...] Ferdinand II (1810-1859) by the Grace of God King of the Kingdom of the Two Sicilies (...) We have decree as follows. Article I. The village of Favarotta ceases to belong to the town of Cinisi, remaining aggregate as far as the seashore to the town of Terrasini. The town of Cinisi preserves the entire its current territory. 2. Our Minister and Secretary of State for Foreign Affairs of Sicily (…), and our Council of State (…) are in charge of the execution of this decree [... ]”).
10. See Vera Von Falkenhausen, “L'incidenza della conquista normanna sulla terminologia giuridica e agraria nell'Italia meridionale e in Sicilia”. In AA.VV., “Medioevo rurale”, edited by V. Fumagalli-G. Rossetti, Bologna, Il Mulino, 1980: 225-226
11. See Falkenhausen, p. 225 note 15
12. See M. Amari, “Storia dei Musulmani di Sicilia”, Firenze, Le Monnier, 1868, Vol. III: 233
13. See F.M. Emanuele e Gaetani, “Appendice Alla Sicilia Nobile” , 1775, Vol. I: 60
14. See F. Maurici, "Illi de domo et familia Abbatellis," Officina di studi medievali, 1985: 19 footnote 63
15. See G. Frangipani, “Storia del convento di San Martino presso Palermo”, 1905: 42
16. See O. Cancila, “Storia dell'industria in Sicilia”, Bari, Laterza, 1995: 160