Definition of "lettuce"

An edible plant, Lactuca sativa and its close relatives, having a head of green and/or purple leaves.  examples

(uncountable) The leaves of the lettuce plant, eaten as a vegetable; as a dish often mixed with other ingredients, dressing etc.  examples

(uncountable, US, slang) United States paper currency; dollars.  quotations

A strong yellow-green colour, like that of lettuce (also called lettuce green).  examples

(uncountable, slang) weed or marijuana

(uncountable, slang) long hair, as worn by an exemplar of bro culture