dēmentĭa, ae, f [demens], the being out of one’s mind; insanity, madness; folly (freq. and class.; for syn. cf.: amentia, furor, rabies, vecordia, insania, deliratio, vesania): animi affectionem lumine mentis carentem nominaverunt amentiam eandemque dementiam, Cic. Tusc. 3, 5, 10; Ter. Ad. 4, 7, 40; Lucr. 1, 705; Cic. Cat. 4, 10, 22; Nep. Pelop. 3, 2; Caes. B. G. 4, 13; Sall. C. 42, 2; Quint. 7, 3, 2; Tib. 1, 2, 11; Verg. E. 2, 69; id. A. 5, 465; 9, 601; Juv. 10, 233; Hor. Epod. 17, 45; Ov. M. 13, 225 al.
In plur., follies, Cic. Att. 9, 9 fin.