Lewis & Short

maestĭtūdo (moest-), ĭnis, f. [maestus], sadness (ante- and post-class., for maestitia), Att. ap. Non. 136, 24 (Trag. Rel. v. 616 Rib.): ego sum miser, cui tanta maestitu do obtigit, Plaut. Aul. 4, 10, 1; Cael. Aur Tard. 1, 4, 104; Sulp. Sev. Ep. 2, 2: captivitatis maestitudinem (societate) consolari, Pall. 1, 26, 2: animi, Ambros. de Vid. 6, 36.