καταστωμύλλομαι · katastōmyllomai — LSJ
chatter, οἷα κατεστωμύλατο οὐκ ἄκαιρα (Dind. κἀστωμύλατο) Ar. Th. 461: pf. part. κατεστωμυλμένος a chattering fellow, Id. Ra. 1160, Numen. ap. Eus. PE 14.5.
in pass. sense, τὰ κατεστ. things blabbed out, EM 524.31.