genuine: P. ἀληθινός.
true: P. and V. ἀληθής, V. ἔτυμος (also Plato but rare P.), ἐτήτυμος.
exact: P. and V. ἀκριβής.
ἐνίστημι, ἀντιτυγχάνω, ἄρτι