powerful
From LSJ
English > Greek (Woodhouse)
adjective
strong: P. and V. μέγας, ἰσχυρός, V. κραταιός, ὄβριμος, καρτερός, ἐγκρατής, παγκρατής, σθεναρός, P. ἐρρωμένος.
mighly: P. and V. δυνατός. Ar. and V. μεγασθενής, ἄλκιμος (rare P.).
efficacious: P. and V. δραστήριος.
convincing (of an argument): P. also V. πιθανός; see convincing.
intense: P. also V. ἔντονος, σύντονος.
be powerful, v.: P. also V. δύναμαι, δύνασθαι, ἰσχύειν, Ar. and V. σθένειν.