no joke noun 2phrase 1 noun2 •Something that should be taken seriously; not something that should be laughed about.Treason-felony, we repeat, is no joke; but then no more is penal servitude for nine years. — 1893 •(informal) Something that is unusually difficult or painful.In addition, Papa was no doubt influenced by his obsession that life is hard, is meant to be hard, and is no joke at all. — 1985 phrase1 •Emphasizing the seriousness or truthfulness of a statement.Well over a hundred urban warriors who weren't afraid to die had a bone to pick with me. No joke. — 2011