1. 1. A spiny, Asian evergreen tree (Citrus limon) widely cultivated for its yellow, egg-shaped fruit.
   2. The fruit of this tree, having a yellow aromatic rind and juicy, acid pulp.
2. Lemon yellow.
3. Informal. One that is unsatisfactory or defective: Their new car turned out to be a lemon.

1. Lemon-yellow.
2. 1. Made from lemons.
   2. Tasting or smelling like lemons.

[Middle English limon, from Old French, from Old Italian limone, from Arabic laymūn, līmūn, from Persian līmūn.]

WORD HISTORY   Although we know neither where the lemon was first grown nor when it first came to Europe, we know from its name that it came to us from the Middle East because we can trace its etymological path. One of the earliest occurrences of our word is found in a Middle English customs document of 1420-1421. The Middle English word limon goes back to Old French limon, showing that yet another delicacy passed into England through France. The Old French word probably came from Italian limone, another step on the route that leads back to the Arabic word laymūn or līmūn, which comes from the Persian word līmūn.

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.