To look at a girl with lust, without making it obvious. to check out a girl or guy. Usually means to look at someone's body, not meant for eye contact.
You can glance that the girl for a bit man, but dont graze her too hard, she will see you staring at her after a while.
Before stepping into the shower I walked behind my wife and let my penis brush across her ass. She looked back at me disapprovingly and asked what I was doing. I said "you've just experienced an episode of graze anatomy."