ἀποπαλμός
From LSJ
τὸ δ' ἐξαίφνης τὸ ἐν ἀναισθήτῳ χρόνῳ διὰ μικρότητα ἐκστάν → suddenly refers to what has departed from its former condition in a time imperceptible because of its smallness
English (LSJ)
ὁ,
A rebounding, Epicur.Ep.1p.8U.
German (Pape)
[Seite 318] ὁ. das Abprallen, Zurückspringen, Epicur. bei Diog. L. 10, 44.