Is graze a noun

Yes, the Word 'graze' is both a noun and a verb.

Noun: a break in the skin most often caused by a scrape or abrasion, with little or no bleeding. Example: I'm OK, just a graze on my elbow.

Verb: to feed on growing herbage, algae, or phytoplankton; to move an animal into an area to eat grass. Example: We take the sheep to graze in a pasture.

Verb: to brush against in passing; to break the surface of the skin. Example: Take your time or you'll graze the door frame as you back in.