Joke

Antonyms of joke:
dulness, seriousness, sobriety, solemnity, stolidity, stupidity, gravity, homage, tribute, darling, favorite, pet.
Examples of usage:
  1. But this is no joke, Fred.
    "The Go Ahead Boys on Smugglers' Island", Ross Kay.
  2. I guess it was just somebody playing a joke on you."
    "Philo Gubb Correspondence-School Detective", Ellis Parker Butler.
  3. " You can make a joke of it, when I-.
    "The Duke's Children", Anthony Trollope.