grass-eater
nounUK /ˈɡrɑːsˌiːtə/
US /ˈɡræsˌiːtər/
An animal that eats grass.
The cow is a grass-eater that spends most of its day in the field.
OTHER MEANINGS
2. A person who eats only vegetables and plants.
My uncle is a strict grass-eater and never touches meat.
3. A fish that feeds mainly on water plants.
The pond is full of small grass-eaters nibbling at the weeds.
4. A lazy person who does little work.
Don't be such a grass-eater—help us finish the job.