look up any word, like swag:
 
3.
When a guy is in such a grumpy, pissed-off state, it's like he has male PMS.

A very irratible dude. Is known to become easily pissed off, brash, rude and sarcastic.
Dude, I was at TMobile the other day, and the guy helping me was totally gillin. I asked him to show me how to change the apps on my phone and he totally bit my head off!
by RonnieDelS June 22, 2010
 
1.
extreme pimpin, seven gurls or more
dating 7 gurls at once, and not having any of them know = gillin
by saia January 19, 2006
 
2.
Coming from the verb 'to Gil'; talking closely in someone's personal space in a most annoying manner, causing severe discomfort.
Sean: "Why you steppin' up? There's no need for gillin'"

Sam: Cut it out, you're gillin' me!
by Sam McGee August 12, 2006