lettuce
Synonym discussion
Sense: noun/1
Lettuce, greens, salad, and cabbage all refer to edible plants but are not interchangeable. Lettuce is a specific leafy vegetable with a mild flavour and crisp texture, most often eaten raw. 'Greens' is a broader, informal term for any leafy vegetables used in salads or cooking (spinach, kale, collards). 'Salad' is the name of a dish, not a single ingredient — calling lettuce 'salad' is a common learner mistake. Cabbage is firmer and is usually cooked or fermented, though it can also be shredded raw in coleslaw. For example: 'I bought a head of lettuce for sandwiches' (specific vegetable), 'Eat your greens!' (any leafy vegetable), and 'Would you like a salad with that?' (a dish, not a leaf).
Etymology
Lettuce comes from Latin lactūca, which comes from lac ('milk'), because lettuce stems have a milky white juice. The word travelled into English through Old French laictue and Middle English letuse.