/ri sep"teuhr/ , n.
1. Physiol. an end organ or a group of end organs of sensory or afferent neurons, specialized to be sensitive to stimulating agents, as touch or heat.
2. Cell Biol. any of various specific protein molecules in surface membranes of cells and organelles to which complementary molecules, as hormones, neurotransmitters, antigens, or antibodies, may become bound.
3. the panlike base of a stall shower.
[ 1400-50; late ME receptour receptor. See RECEPTION, -TOR ]