jest. n. 1. A playful or frivolous mood or manner: spoken in jest. 2. A playful remark; a witticism or joke. 3. A playful or amusing act; a prank.4.he Farmer's servants rushed up with sticks and pitchforks and soon taught the Ass that clumsy jesting is no joke. Fables by Aesop View in context. To tell you the truth, I had supposed that YOU were jesting in your letter; wherefore, my heart was feeling heavy at the thought that you could feel so displeased with me.