The act of sticking your hand up a girl while she's on her period and pulling out the biggest chunk of clot you can find (occasionally rolling up multiple clots into a sphere) and either throwing or eating them, most commonly the latter.
"Dude, my girlfriend let me glorb her last night! It was awesome"
"I need to find someone that's okay with glorbing during sex"
When the chick is using both her hands in a spherical, globe-like shape, during a blowjob. Going the extra mile, involving the boner and scrotum throughout the process.
Grant was too drunk to finish last night until Holly started globing him, which led to a quick climax.