Slosh-knob 

A term used to describe the poor state of one's penis after engaging in acts of sex with a less-than-desirable partner. The prefix 'slosh' could indicate that the penis is infected with an STI or in mangy condition as a result of the recent intercourse.

"Hey Jim, you and your slosh-knob can get the fuck away from me! I know where you've been putting that thing lately!"

Slosh-knob by Jo-Ho999 March 4, 2010

slosh my knob 

Sloshing the knob is a phrase for a blowjob.

Sloshing is the noise of water or liquid (an onomatopoeia).

Knob is slang for a penis.

Hence, sloshing the knob constructs the imagery of a blowjob.

Variations include sloshing the knob, sloshing my knob, would you like your knob sloshed, and so forth.

Daniel: Hey, want to slosh my knob?
Alyssa: Not now, I have morning breath.

slosh my knob by secretyellowjedi June 1, 2011