A joke played on an innocent victim, where several people agree beforehand to laugh at a completely pointless joke involving elephants, polar bears, etc. in a bathtub with the punch line "no soap ... radio". The objective is to see if they can get the victim to laugh along so he won't look like he was too dumb to get it. If he does, then everyone stops laughing and asks the victim what's so funny, and gets a good laugh at his embarassment.
We used to do the old "no soap...radio" joke when we were 10.
by JohnJabong May 2, 2006
punchline to a joke with No point. The joke is on you if you laugh. circa 1960
Two kangaroos are in the bathtub.
One kangaroo says, "Pass the soap."
The other kangaroo says, "No soap...radio!"
by smokeyX September 30, 2005
Punchline to a joke only you understand.
Two elephants are in the bathtub.
One elephant says, "Pass the soap."
The other elephant says, "No soap...radio!"
by wanderlust December 11, 2003
An awsome joke in which the joke is on one of the listeners.

The teller will have a group of friends who know what is going to happen. The teller then asks somone who is not in on the joke if he would like to hear a joke. The teller tells a story that makes absolutely no sense and is not humorous, and finishes it with the line "No soap, Radio!". The friends in on the joke then burst out into laughter.

The friends in on the joke then get to see the reaction of the friend not in on the joke. Will he laugh at a pointless joke to try to fit in, or will he make an ass out of himself trying to understand it?
Teller: ... so there's this elephant sitting in a bathtub and he says to the gorilla, "No soap, Radio!"
People in on it: Ha ha ha!
Not in on it: *unsure* Ha, ha?
All others: Ha, moron.
by unqu3nch4bl3fir3 September 25, 2006