1.A substance, usually a peptide or steroid, produced by one tissue and conveyed by the bloodstream to another to effect physiological activity, such as growth or metabolism.
2.Any of various similar substances found in plants and insects that regulate development.

[From Greek hormon present participle of horman, to urge on, from horme, impulse.]

- hormon?al (-m?n?l) or hormon?ic (-mon?ik) adjective
- hormon?ally adverb

Excerpted from The American Heritage Dictionary of the English Language, Third Edition Copyright © 1992 by Houghton Mifflin Company. Electronic version licensed from Lernout & Hauspie Speech Products N.V., further reproduction and distribution restricted in accordance with the Copyright Law of the United States. All rights reserved.