When your girlfriend or boyfriend (whatever preference may be) walks by while reaching out to bump your crotch with their hand. Not to be confused with a grope, it's just a quick tap, to let you know they're thinking of the guy downstairs.
We were just cleaning house and all of a sudden she walked past me and gave me a junk bump... then it was time to clean naked!
by Naughty lil French Maid July 08, 2009
When a girl intentionally bumps up against a guy's junk either to check out his package or see if she can get a rise. Supposed to seem accidental or not be noticed at all like she did so unintentionally.
After she "junk bumped" him, she discovered right away that he found her attractive.
by Teera February 09, 2007