Definition
A person trained to pilot, navigate, or serve as a crew member aboard a spacecraft operating beyond the Earth's atmosphere.
Plain English
Someone trained to fly or work in a vehicle that travels into space.
Context Anchor
Seen in aviation and aerospace discussions, especially when comparing aircraft flight with spaceflight.
Derivation
From the Greek 'astron' meaning 'star' and 'nautes' meaning 'sailor.' Literally, 'a sailor among the stars.' The word was built on the older pattern of 'aeronaut' (air sailor) and 'argonaut' (the legendary sailors of the Argo).
Intuition Check
An astronaut is not just a pilot flying very high. The word refers to a person trained for travel or work in space.
Example Sentence 1
Several early astronauts came from the ranks of military test pilots.
Example Sentence 2
Commercial space companies now hire astronauts from traditional aviation backgrounds.