No, “astronaut” is not a pronoun; it is a noun. Specifically, it is a common noun used to refer to a person who is trained to travel and work in space.
Explanation of Terms:
- Pronoun: A word that replaces a noun in a sentence (e.g., he, she, it, they).
- Noun: A word that names a person, place, thing, or idea (e.g., astronaut, teacher, Earth).
For example:
- In “The astronaut is preparing for the mission,” “astronaut” is the noun.
- If replaced with a pronoun: “He is preparing for the mission.”
So, “astronaut” is not a pronoun but a noun.