ὁλοός

From LSJ

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

Source

Greek Monotonic

ὁλοός: ὁλοόφρων, βλ. οὔλλω.