* ἰσχυρός (ischyros): This is a general word for strong, powerful, or forceful. It's a good all-purpose option.
* δυνατός (dynatos): This means "powerful," "able," or "capable," implying strength of ability rather than just physical strength.
* ἀνδρεῖος (andreios): This translates to "brave," "manly," or "courageous." Strength of character is implied.
* ρωμαλέος (rōmaléos): This specifically refers to physical strength and robustness.
Therefore, the "best" translation depends heavily on what kind of strength you are referring to.