1. Physiology A specialized cell or group of nerve endings that responds to sensory stimuli.
2. Biochemistry A molecular structure or site on the surface or interior of a cell that binds with substances such as hormones, antigens, or neurotransmitters or is activated by events such as a change in the concentration of an ion.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.