A lot vs. Alot: 9 Grammatical Pitfalls
"the state of one who dotes," c.1300; see dote + -age. Originally of all sorts of mental impairment, not just that resulting from old age. First recorded late 14c. for "senility."
dotage dot·age (dō'tĭj)n. The loss of previously intact mental powers; senility. Also called anility.