1775, from garlic + -y (2). The -k- perhaps to preserve the hard -c-, but garlick was a former alternative spelling.
Entries linking to garlicky
garlic n.
"onion like bulbous plant allied to the leek, known to the ancients and much used in cookery," Middle English garlek, from Old English garlec (West Saxon), garleac (Mercian), "garlic," from gar "spear" (in reference to the clove), see gar, + leac "leek" (see leek). Garlic-bread is attested by 1947.
-y 2
adjective suffix, "full of or characterized by," from Old English -ig, from Proto-Germanic *-iga- (source also of Dutch, Danish, German -ig, Gothic -egs), from PIE -(i)ko-, adjectival suffix, cognate with elements in Greek -ikos, Latin -icus (see -ic). Originally added to nouns in Old English; used from 13c. with verbs, and by 15c. even with other adjectives (for example crispy). Adjectives such as hugy, vasty are artificial words that exist for the sake of poetical metrics.