eager beaver noun

1. an enthusiastic person who works very hard

[TahlilGaran] English Dictionary ▲

eager beaver
a person who is always eager to work hard or do something extra; someone who works very hard and is very enthusiastic
My colleague is an eager beaver and is always ready to work hard when we need him.

The woman is an eager beaver and I am sure that she will do very well in this company.

The young girl was an eager beaver and always came to class before the other students.

[TahlilGaran] English Idioms Dictionary ▲

eager beaver
n. phr., slang A person who is always eager to work or do anything extra, perhaps to win the favor of his leader or boss.
Jack likes his teacher and works hard for her, but his classmates call him an eager beaver.
The man who was promoted to be manager was an eager beaver who got to work early and left late and was always offering to do extra work.

[TahlilGaran] English Idioms Dictionary ▲