noun
Refers to a person who jokes around, acts silly, or plays pranks; often lighthearted, but can carry a negative nuance of being a fool or idiot depending on context.
彼はクラスのおどけ者で、いつもみんなを笑わせている。
He's the class joker, always making everyone laugh.
あのおどけ者がまた変なことを言い出した。
That fool has started saying weird things again.
From the verb 戯ける (おどける, 'to jest, fool around') + 者 (もの, 'person'). The verb itself is of uncertain origin, possibly related to 戯れ (たわむれ) or other playful-sound words.