ἀμύνω

Etymology
If the nasal is originally a present marker, as in and, we have a root ἀμυ-, which may be found in , but the semantics are. Perhaps related to.

Verb

 * 1)  to keep off, ward off, defend, guard, assist
 * 2)  to avenge, punish, repay, requite

Usage notes
Generally, the object being protected received the accusative case, while the offending object receives the dative. The second sense, "avenge" is more common in the middle voice.