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1.
Incredibly gregarious, life of the party, a bit wildly fun but with a heart o' gold. sweet, insane, party, trippin'
Your new friend Tony was totally jacco last night at the club -- crackin' us all up, dancing up a storm. Cool guy.
by ziquemu April 24, 2008
 
2.
1) n., one who gets left behind for the benefit of other people

2) v., to leave someone behind so a different group can find him/her
1) Guy 1: Hey, where's John?
Guy 2: You know that really annoying girl?
Guy 1: The one from Math?
Guy 2: Yeah, we ran into her earlier. He went with her over to a hot dog stand and we ran.

Guy 1: Oh, poor jacco.

2) Quick! While he's in the bathroom, let's jacco him! Nic and his gang'll be around sometime today.
by CDoodles June 05, 2009