grass vs grass over

grass is a noun but grass over is not a noun.

Word	Noun	Adjective	Verb	Adverb
grass	Yes	No	Yes	No
grass over	No	No	Yes	No

As verbs, grass and grass over are synonyms defined as:

grass (noun)	grass over (noun)
street names for marijuana
bulky food like grass or hay for browsing or grazing horses or cattle
a police informer who implicates many people
narrow-leaved green herbage: grown as lawns; used as pasture for grazing animals; cut and dried as hay

grass (verb)	grass over (verb)
give away information about somebody	cover with grass
shoot down, of birds
feed with grass
cover with grass
spread out clothes on the grass to let it dry and bleach