Prō'emp-tō'sis, n.

(84), n. [Gr. προεμπίπτειν, to fall in before, from πρό, before, and ἐμπίπτειν, to fall in, from ἐν, in, and πίπτειν, to fall.] (Chron.) The lunar equation, or addition of a day, necessary to prevent the new moon from being reckoned as happening a day too soon. Brande.