βολεύς
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
German (Pape)
[Seite 452] ὁ, der Werfer, Tzetz. Anteh. 393.
Greek (Liddell-Scott)
βολεύς: έως, ὁ, σφενδονήτης, Τζέτζ. π. Ὁμ. 393.