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mighty: P. and V. δυνατός, Ar. and V. μεγασθενής, ἄλκιμος (rare P.).
strong: P. and V. μέγας, ἰσχυρός, V. κραταιός, ὄβριμος, ἐγκρατής, καρτερός, παγκρατής, σθεναρός, P. ἐρρωμένος; see strong.
efficacious: P. and V. δραστήριος.