A somewhat formal or literary term for a toy or something to play with; not an everyday word for children's toys.
He treats life like a plaything.
That antique is not a mere toy; it has historical value.
losing sight of one's goal by indulging in trivial pursuits
From 玩 (play with, toy with) + 物 (thing). The exact historical derivation is uncertain, but the kanji compound directly suggests 'plaything'.