rə̇ˈseptə(r), rēˈ- noun
( -s )
Etymology: Middle English receptour, from Middle French, from Latin receptor, from receptus (past participle of recipere to receive) + -or
1. : one that receives: as
a. : a part of the body (as a cell, group of cells, complex organ) that is especially sensitive to alteration of some environmental factor (as light or sound waves, temperature, pressure), that undergoes specific stimulation when exposed to such alteration, and that transmits impulses arising from such stimulation to the central nervous system : sense organ — distinguished from effector
b. : a body or surface sensitive to radiation : a surface illuminated in making a color test
c. : stock 5b(1)
d. : the part of a stall shower that receives and drains away the water
2. : the chemical groups or groupings of an antigen or hapten that combine specifically with the corresponding groups of antibody : chemical groups of a cell that combine especially with antibodies or viruses