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, drugs, or neurotransmitters.

1. A protein on a cell wall that binds with specific molecules so that they can be absorbed into the cell in order to control certain functions.
2. any specialized cell or structure that responds to sensory stimuli.

1. A molecular complex of a cell through the union with which alien cell-products or cell-constituents can produce, their specific effects upon the coll. these same receptors, owing to the presence of which the cell is open to attack, when cast off from the cell constitute its most effective defenses. also called side-chain. see immunity, 5.
2. in wireless telegraphy, a receiver.
3. the terminal expansion in skin or mucous membranes of a sensory nerve.

1. a cellular structure that is postulated to exist in order to mediate between a chemical agent that acts on nervous tissue and the physiological response
2. an organ having nerve endings (in the skin or viscera or eye or ear or nose or mouth) that respond to stimulation