inter-menstrŭus, a, um, adj.,
between two months : lunā intermenstruā, i. e. at the time of new moon , Plin. 18, 32, 75, § 322.—Subst.: intermenstrŭum , i. n. (sc. tempus), the new moon , time of new moon , Varr. R. R. 1, 37, 1; Cic. Rep. 1, 16, 25: tempore intermenstrui, Amm. 20, 3, 11.