Play

Antonyms of play:
tautness, tightness, drudgery, labor, work, duty, obligation, responsibility, earnestness, gravity, seriousness, soberness, sobriety, solemnity, earnest, disuse, nonuse.
Examples of usage:
  1. Would he play to us, do you think?
    "The Way of Ambition", Robert Hichens.
  2. I did play the fool so ...
    "Arsene Lupin", Edgar Jepson Maurice Leblanc.
  3. Well, prince, cried she as they began to play, what do you think of me by morning light?
    "The Necklace of Princess Fiorimonde and Other Stories", Mary De Morgan.