ecofreak
/ˈikoʊˌfrik/
noun
- An informal, sometimes mildly humorous term for a person who is very enthusiastic about protecting the environment.
- Some people call her an ecofreak because she refuses to use plastic.
- My uncle is a total ecofreak — he composts everything and bikes everywhere.
- The ecofreak in our office always reminds us to recycle.
Synonyms