1. The persistent conviction that one is or is likely to become ill, often involving symptoms when illness is neither present nor likely, and persisting despite reassurance and medical evidence to the contrary. Also called hypochondriasis.
2. Plural of hypochondrium.

[Late Latin, abdomen, from Greek hupokhondria, pl. of hupokhondrion, abdomen (held to be the seat of melancholy), from neuter of hupokhondrios, under the cartilage of the breastbone : hupo-, hypo- + khondros, cartilage.]

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.