To bring fury from the sky.
Get after it like it owes you money.
To aggressively get fucked up. To go big. To consume party drugs and alcohol in an effort to become extremely wasted, yet still fired up enough to stay up late.
Hey guy, let's get after it tonight!
(v.) 1. To exert a great deal of effort in pursuance of some worthy goal 2. To perform coitus in a manner satisfactory to both (or all) parties involved
"Get after it dude!"
"Sorry man, I can't go to the hookah bar tonight, I've got to get after it with my girlfriend."
To do it. To go hard. To go balls deep. To accomplish something. To improve upon a life-skill. To party with the sickest group of skiers or snowboarders this planet has ever seen.
She's checking you out. Get after it.
You're gonna be late for your pap-smear? You better go get after it.
You didn't land that jump? You didn't get after it enough.
1.The act of finding any slut that wants the dick
"That bitch just eyefucked the shit out of me, time to get after it."