E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Wight (Isle of)
means probably channel island. (Celtic gwy, water; gwyth, the channel.) The inhabitants used to be called Uuhtii or Gwythii, the inhabitants of the channel isle.
According to the famous Anglo-Saxon Chronicle, the island is so called from Wihtgar, great grandson of King Cerdic, who conquered it. All eponymic namesthat is, names of persons, like the names of places, are more fit for fable than history: as Cissa, to account for Cissanceaster (Chichester); Horsa to account for Horsted; Hengist to account for Hengistbury; Brutus to account for Britain; and so on.