Definitions

1. noun

A person who travels in a spacecraft, especially to the moon or other planets.

“The astronaut spent six months on the International Space Station.”

2. noun

A person who operates a spacecraft or its systems, especially in space exploration.

“The team of astronauts worked together to repair the malfunctioning satellite.”

3. noun

A person who has been sent to space as part of a space mission, often as a test subject for space travel.

“The astronaut was part of the historic mission to walk on the moon.”