1. someone energetic and enthusiastic
a real eager beaver who gets stuck in
An eager beaver is a noun describing a person who is happily enthusiastic. energetic and zealous. This is an informal expression and you might use it to describe someone who is always early, who usually volunteers for extra tasks, or who is very enthusiastic. Sometimes the 'eager beaver' makes other employees or workers look bad by comparison and in these situations calling someone an eager beaver may be regarded as negative.