‘And thou wilt come to the isle Thrinacia. There in great numbers feed the kine of Helios and his goodly flocks, seven herds of kine and as many fair flocks of sheep, and fifty in each.’’   Odyssey 12.127ff.  (online text: Eng.Grk.)

Scholarship has long assumed that Trinakria (Τρινακρία) is related to Homer’s Thrinacia (Θρινακίη). It is widely suspected that the name is derived from treis arkai (τρεῖς ἄκραι), and was an erroneous ‘correction’ of the name Thrinacia, owing to increased awareness of Sicily’s roughly triangular shape since the time of Homer. 

Ancient Localization

Thucydides, History of the Peloponnesian War 6.2

 

Strabo, Geography 6.2.1

 

Justin, Epitome of Pompeius Trogus 4.2

“At first Sicily had the name of Trinacria; afterwards it was called Sicania. It was originally the abode of the Cyclops…”
(online text: Eng.Lat.)

Pliny, Natural History 3.8

“But more celebrated than all is Sicily, called Sicania by Thucydides, and by many writers Trinacria or Trinacia, from its triangular appearance.”
(online text: Eng.Lat.)