sĕvērĭtūdo — Lewis & Short
sĕvērĭtūdo, ĭnis, f.1. severus,
I gravity, austerity, severity (ante- and post-class. for the class. severitas): (frontis) Plaut. Ep. 5, 1, 3 (also cited Non. 173, 10):
morum,App. M. 1, p. 113, 41.