ἀποστατεῖν

From LSJ

Γελᾷ δ' ὁ μωρός, κἄν τι μὴ γέλοιον ᾖ → The fool laughs even when there's nothing to laugh at

Menander

Greek > English (Woodhouse Verbs Reversed)

(see also: ἀποστατέω) be absent, be distant, be far, leave in the lurch, sland aside, stand aloof, stand apart