medilunius

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.

mĕdĭlūnĭus, a, um, adj. [mediusluna],

in the middle of the month, having half a disk, half-orbed (post-class): (luna) primo est corniculata, deinde medilunia, Mart. Cap. 7, § 738.