From Longman Dictionary of Contemporary Englishbe a jokebe a jokeinformalSTUPID/NOT SENSIBLE to be completely useless, stupid, or unreasonable The whole meeting was a joke. → joke
Examples from the Corpus
be a joke• I wasn't entirely sure whether he was joking or not.• Nerf Herder is a joke band.• Some of this is very serious, and some of it is joking around.• When women do confront sexism, the glib reply is often that it is a joke.• It is a joke and I told Wilkinson so.• The Window Rock Tribal Jail is a joke to criminals and police officials alike.• Here two young men were joking with a gun.• Well, there are jokes about yeast infections, frostbite, liver transplants and cereal variety packs. 