Meaning

adjective vigorously passionate

adjective endowed with or exhibiting great bodily or mental health

originFrom Middle English lusty (“mirthful, pleasant, delicious, delightful”), equivalent to lust + -y. Compare Saterland Frisian lustich (“amusing”), West Frisian lustich (“amusing, funny”), Dutch lustig (“cheerful”), German lustig (“amusing”), Danish lystig (“merry”), Swedish lustig (“funny”).

Etymology from Wiktionary, CC BY-SA 3.0