The Collaborative International Dictionary of English v.0.48:
astronaut \as"tro*naut\ adj. a person trained to travel in a spacecraft; one who travels in a spacecraft; -- called in the Soviet Union and Russia cosmonaut. Syn: spaceman, cosmonaut [WordNet 1.5]WordNet (r) 3.0 (2006):
astronaut n 1: a person trained to travel in a spacecraft; "the Russians called their astronauts cosmonauts" [syn: astronaut, spaceman, cosmonaut]