ki•ninPronunciation: (kī'nin, kin'in), [key]
any of a group of hormones, formed in body tissues, that cause dilation of blood vessels and influence capillary permeability.
a combining form used in the names of hormones, esp. peptide hormones: bradykinin; cytokinin.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.