φθειρικός
From LSJ
ἵνα οὖν μηδ' ἐν τούτῳ δῷ αὐτοῖς λαβήν (Photius, Fragments on the Epistle to the Romans 483.26) → so that he doesn't give them even here a handle (= an opportunity for refutation)
German (Pape)
[Seite 1270] von Läusen, Läuse betreffend (?).
Greek (Liddell-Scott)
φθειρικός: -ή, -όν, ὁ ἀνήκων ἢ ἁρμόζων εἰς φθεῖρας, Γλωσσ.