a. Any of various plants of the genus Lactuca of the composite family, especially L. sativa, cultivated for its edible leaves.
b. The leaves of L. sativa, used especially in salads.
2. Slang Paper money.
[Middle English lettuse, from Old French laitues, pl. of laitue, from Latin lactūca, from lac, lact-, milk (from its milky juice); see melg- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.