Lewis & Short

* bilbo, ĕre, v. n. [onomatop.], to make a noise like that of a liquid agitated in a vessel: bilbit factum est a similitudine sonitus, qui fit in vase. Naevius Bilbit amphora inquit, Paul. ex Fest. p. 34 Müll. (Com. Trag. v. 124 Rib.): bilbit βομβύζει, Gloss.