καθῆραι
From LSJ
χαῖρ', ὦ μέγ' ἀχρειόγελως ὅμιλε, ταῖς ἐπίβδαις, τῆς ἡμετέρας σοφίας κριτὴς ἄριστε πάντων → all hail, throng that laughs untimely on the day after the festival, best of all judges of our poetic skill
English (LSJ)
καθήρας, aor. 1 inf. and part. of καθαίρω.
Greek (Liddell-Scott)
κᾰθῆραι: καθήρας, ἀπαρ. καὶ μετοχ. ἀορ. α΄ τοῦ καθαίρω.