The headword phrase (in which 'dumb' bears the meaning it bears in UK, not US, English) is Eubulus fr. 29 Kock, now 28 K.-A. (Suda ms.F wrongly gives the title as Dionysus). For the present gloss on it see also Photius kappa1337 Theodoridis, and cf. Zenobius 4.66 and other paroemiographers.
Its adjective kwfo/teros is the comparative of kwfo/s: cf. kappa 2310, kappa 2307, kappa 2308.