1. Slang. (positive) - to propound; to sanctify; to advocate the genuineness/veracity of another's character.
2. Slang. (negative) - to A.)acknowledge and accept partial responsibility for the presence/actions of another person and the effects thereof, or B.)to deny all responisbility and/or attachment to said individual and/or their actions and any effects thereof.
1. (positive scenario - your friend's party)
"Who's the dude you came in with?"
"Oh, that's Keebler. Don't worry, man. I co-sign for him. He's cool."
2. (negative scenario - some random party)
"I think your buddy's about to get his ass beat."
"Who said he's my buddy? I just walked in next to him, I didn't co-sign for him."
To agree with. This term is mostly used on message boards.
User1: DAMN! J.Lo gotta fat ass!
A Slang Word Meaning "Vouch", When You Get Someone A Job Where You Work. If The Person Is Working Out Then The "Co-Signer" Usually Takes Credit For The Employee's Success(Behind Their Back Usually).
Justin: "Holy Shit, My's Like The Best Employee We Got, Including Myself, Look All The Work He Did Last Night By Himself!"
Tommy: "Yeah, That's Right I Co-Signed That Kid."