Luscious
late Middle English: perhaps an alteration of obsolete licious, shortened form of delicious.
wiktionary
From earlier lushious, lussyouse(“luscious, richly sweet, delicious”), a corruption of lustious, from lusty(“pleasant, delicious”) + -ous. Shakespeare uses both lush (short for lushious) and lusty in the same sense: "How lush and lusty the grass looks" (The Tempest ii. I.52).
An alternative etymology connects luscious to a Middle English term: lucius, an alteration of licious, believed to be a shortening of delicious.
etymonline
luscious (adj.)
late 15c., according to The Middle English Compendium a variant of Middle English licius "delicious" (c. 1400), which is a shortening of delicious, with the variant form perhaps influenced by Old French luxure, lusure. But OED 2nd ed. and Century Dictionary are against all this and the former considers it "of obscure origin" while the latter suggests lusty with a pseudo-Latin ending. John Palsgrave, the 16c. grammarian, spelled it lussyouse. Related: Lusciously; lusciousness.
