Receptor comes from Latin receptor ('one who receives'), from receptus, past participle of recipere ('to receive'), from re- ('back') + capere ('to take'). The historical chain includes Latin receptor and Latin capere. Older glosses in the chain include "one who receives", "to receive", "back", and "to take", which help explain the semantic range of the modern word. Morphologically, receptor is best read as compound and borrowing, yielding an English noun shaped by both form history and later usage. In current English it functions as a noun, with the sense "a cell or molecule that detects a stimulus and responds to it". related forms include receive, reception, receptive, and receptacle. The result is an English noun whose etymology preserves the older forms while supporting the word's specialized modern meaning.