Lettuce (noun)

1. A plant of the daisy family, with a head of edible leaves.
2. Leaves of this plant used as a salad vegetable.

Origin:

From middle english letuse, from old french letues, from latin lactūca ("lettuce"), from lac ("milk"), because of its milky sap.

Examples:

1. He planted lettuce in his garden.
2. She added lettuce and tomato to her sandwich.
3. We had a Caesar salad with lettuce, croutons, and Caesar dressing.
4. The lettuce in the salad was crisp and fresh.
5. Lettuce is a good source of Vitamin K, Vitamin A, and Vitamin C.