Ἄαπτος

[Meaning someone/something] unharmed.
Herodianus¹ says about a)/aptos that it comes from i)a/ptw ['I harm'], and after adding alpha-privative and dropping the 'i' [it becomes] a)/aptos, "whom no one can harm." Or perhaps the 'a' is not to be taken as negative but as intensifying, so it would be "one who has great power to harm." Thus the first has a passive sense, the second an active. With the negative prefix it also means "one who is untouched."²