Lewis & Short

mundŭlus, a, um, adj. dim. [1. mundus], cleanly, neat, trim, nice, spruce (anteclass.): amasii, Plaut. Truc. 3, 1, 13.
Hence, adv.: mundŭlē, neatly, trimly, nicely (post-class.): qui ubi ad Dircaeum fontem adveniunt, mundule nitidantur jugulos quadripedantum, Att. ap. Non. 144, 17 (Trag. Rel. v. 602 Rib.): mundule amicta, App. M. 2, p. 117, 33.