lettuce (n.) Look up lettuce at Dictionary.com
garden herb extensively cultivated for use as a salad, late 13c., letuse, probably somehow from Old French laitues, plural of laitue "lettuce" (cognate with Spanish lechuga, Italian lattuga), from Latin lactuca "lettuce," from lac (genitive lactis) "milk" (see lacto-); so called for the milky juice of the plant. Old English had borrowed the Latin word as lactuce.