I use this term all the time but I guess it’s not really that common, or obvious in meaning.
“Clap humor” is an ostensible joke that isn’t really funny, but which expresses a sentiment with which the audience agrees. They laugh, but they mostly clap. Stand-up comedians will do lame local humor, knowing that people will clap out of recognition. Over the years that I’ve watched him, I’ve seen David Letterman do essentially the same fat jokes about Oprah, Roseanne Barr and Rosie O’ Donnell. Or, you can take any political joke and substitute today’s politician with the original:
A man died and went to heaven. As he stood in front of St. Peter at the Pearly Gates, he saw a huge wall of clocks behind him. He asked, “What are all those clocks?” St. Peter answered, “Those are Lie-Clocks. Everyone on Earth has a Lie-Clock. Every time you lie, the hands on the clock will move.” “Oh” said the man. “And whose clock is that one?” “That’s Mother Teresa’s. The hand have never moved, indicating that she never told a lie.” “Incredible” said the man. “And whose clock is that one?” St. Peter responded, “That’s Abraham Lincoln’s clock. The hands have moved twice, telling us that Abe told only two lies in his entire life.” “Where’s [whoever]’s clock?” asked the man. “[Whoever]’s clock is in Jesus’ office. He’s using it as a ceiling fan.
Other ones include such classics as "He said he killed the pig” and “God doesn’t think he’s [blank]”.
The thing about “clap humor” is that it’s easy. You just set yourself up with a particular audience and rely on their agreement to get half your job done. It is, to some degree, a fair tool in the comic’s toolbox, but it gets old fast, and you have to not care about alienating people.