Pregnant; knocked up. Means literally that "one" kid is "on the way" (will be born soon, and will consume every moment of your spare time with its endless whining). Not a good thing if you have a girlfriend/wife who is not the mother of the baby.
"Just when I thought I said all I could say, my chick on the side says she's got one on the way..." -Usher, "Confessions (Part II)"

Jerry: "Shit man, did you hear? I got one on the way."
Pete: "Awesome. It's good you stopped shooting blanks and finally knocked your wife up."
Jerry: "No...that's the problem. My wife ain't the baby's mama...your 16-year-old daughter is."
Pete: "That dirty slut. I need to get her on the pill."
Jerry: "Word."
by Nick D July 19, 2004
meaning to talk to someone alone or in private. A one on one conversation.
by wusabi May 4, 2006
To think only about oneself. To be selfish.
His is just one way when it comes to doing favors.
by D.David June 18, 2007
Masturbating with oneself.
Greg: "Sarah, Jessica, and I had a three-way last night, son! What you do?!"
Josh: "One-way, dude. One-way."
by ReyCHUL August 24, 2011
when vacationing in thailand you or any one of your friends will buy several inexpensive whores and not share them even when it is obvious you wont be using all of them.
Tom- man, did you see the girls i got?
Bob- yeah, nice choice, mind if i borrow the one in blue?
Tom- sorry, they are all mine
Bob- dude, youre such a fucking one way
by colon plow May 1, 2005
when a group of dudes/girls mess wit or fuck the same girl/dude.basically a team player.
"In the A we fuck wit peepul {da long way},but up in COV i fuck wit dem only one way."
by th@ K!DD January 10, 2010
to be geeked up "rolling hard" on ecstacy
whew im on that one way right now feeling like AY!
by rod biz January 22, 2009