Note 166
From The Invasion of Spain, part of Chapter 51 of the Decline & Fall

The name of Andalusia is applied by the Arabs not only to the modern province, but to the wholc peninsula of Spain (Geograph. Nub. p. 151; D'Herbelot, Biblioth Orient. p. 114, 115). The etymology has been most improbably deduced from Vandalusia, country of the Vandals (D'A l'Europe, p. 146, 147, etc.). But the Handalusia of Casiri, which signifies, in Arabic the region of the evening, of the West, in a word, the Hesperia of the Greeks, is perfectly apposite (Biblioth. Arabico-Hispana, tom. ii.p. 327 etc.).