JAM is a well-known slang word within the UK standing for Just A Minute, a long running popular BBC Radio 4 panel. The slang JAM was first used within the BBC, but this unofficial slang is now far more widespread.
Devised by Ian Messiter (1920-1999) whilst aboard a London bus, JAM was first broadcast in South Africa before being adopted by the BBC in 1967. It is distinctive by its use of the minute waltz.
An extremely entertaining but simple format, celebrity contestants have to speak for one minute on a given subject without deviation, repetition (of a word) or hesitation. If they do, other celebrity panellists can make a challenge; a successful challenge means they in turn get to continue talking on that subject for the remains of the minute. By 2009 over 700 episodes of JAM have been aired.
"Don't telephone me at 6-30 as I'll be listening to JAM on the wireless."
"No chance of that as I'm also a fan of JAM!"