IPA: /ˈneɪvɪʃli/
KK: /ˈnævɪʃli/
In a way that is dishonest or deceitful, often with a playful or mischievous intent.
He knavishly tricked his friends into believing his tall tales.
Knavishly → It is formed from "knave" (from Old English "cnafa", meaning a boy or servant, later implying a dishonest man) and "-ishly" (a suffix meaning in a manner of). The word "knavishly" means in a manner characteristic of a knave, often implying deceitfulness or trickery.
Think of a 'knave' as someone who behaves dishonestly, and the '-ishly' shows how they act. So, knavishly means acting in a deceitful way.