Where does “ἀνάπαιστος” come from?

ἀνάπαιστος (Ancient Greek) comes from Ancient Greek ἀναπαίω, from Ancient Greek ἀνα-, from Ancient Greek ᾰ̓νᾰ́ — up; to, again, upon.

ἀνάπαιστος (Ancient Greek): struck back, rebounding