τερέτισμα

ατος, τό
A. a humming, twanging, φορμίγγων Diog. ap. D.L. 6.104 (alluding to E. Fr. 200), Luc. Nigr. 15, AP 7.612, cf. 11.352 (both Agath.); chirruping of cicadas, Hsch.
II. metaph., a mere sound or twittering, τερετίσματα τὰ εἴδη (the Platonic ideas) Arist. APo. 83a33; τὰ συνήθη ταῦτα τ. the ordinary prattle, Procop.Gaz. Ep. 33; τὸ πόημα οὐχ ὡς τ. καὶ κροῦμα νοοῦμεν Phld. Po. 2p.228H.
Liddell, Scott & Jones
A Greek-English Lexicon, 1940
An open-access project