Mackin' out 

(mah-kin out)

to kiss a partner passionately or what would be considered inappropriately in public (linked with PDA)

similarities to the meaning of making out however mackin' is considered to be early classic American slang

Jane: hey where's Shelley today?

Rachel: totally mackin' out with Martin behind the bleachers

Jane: ew

Mackin' out by offthewall May 19, 2012

Mackin' Out 

Taking part in the locking of lips. Commonly known as smooching, snogging, sucking face, etc. Derived from the more well known, and certainly less interesting, "making out."

"Hey Vanessa, I like you. Wanna go mack out in the woods?"

"Did you see those two mackin' out in the hall yesterday? I thought I was going to projectile vomit it was so repulsive!"

Mackin' Out by NotAPaperGirl December 9, 2008

makin out 

When too people possible a guy and a girl or a girl and a girl or 2 guys are kissing but not just a peck but kissing kissing getting dirty

While Me and herb were kissing they went to makin out then to french kissing then went to under the bridge action

makin out by Jazmah May 16, 2006

MAKIN' OUT WITH SOME BOY 

Usually written in all caps for maximum effect, this is a smug declaration of quasi-random physical affection with someone of the male gender. May result from HEE HEE PET PET and lead to chin-chap and/or BUMPIN' AND LOVIN' IN THE BED.

Dakota smiled lazily and announced to her friend, "My lips are chapped... from MAKIN' OUT WITH SOME BOY last night!"

MAKIN' OUT WITH SOME BOY by Jess Park February 22, 2004