dementia Look up dementia at Dictionary.com
1806, L. noun of state from dementem, from dementer (see dement). It existed earlier in an anglicized form, demency (1520s), from Fr. démence. Dementia præcox is a Mod.L. form recorded from 1899 in Eng., 1891 in Ger., from Fr. démence précoce (1857). See precocious.