γελᾷ δ' ὁ μωρός, κἄν τι μὴ γέλοιον ᾖ → the fool laughs even when there's nothing to laugh at
dull: P. and V. ἀμαθής, ἀσύνετος, ἀφυής, νωθής, Ar. and P. δυσμαθής, P. ἀναίσθητος, βλακικός; see foolish.
