προεμπίπτω

A. fall on or into before, ἡ βολὴ π. τῷ ὕδατι Hld. 9.5; attack first, Ael. Tact. 37.6; take the first step, εἰς γνῶσιν D.L. 4.39.

2. protrude into, c. dat., Gal. UP 7.7; προεμπίπτει τὰ χείλη, of a bear trying to bite a net, Plu. 2.918f.