from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A crisp, round, compact head of lettuce with light green, tightly folded leaves.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A lettuce cultivar noted for its crunchiness; the most familiar of all lettuces sold in the United States.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. lettuce with crisp tightly packed light-green leaves in a firm head
From its pale color.(American Heritage® Dictionary of the English Language, Fourth Edition)