rare. [f. prec. + -ESS.] A female keeper or custodian. b. A woman who keeps a man.
1748. Richardson, Clarissa (1811), VI. 359 (D.). Hardly ever, I dare say, was there a keeper that did not make a keeperess; who lavished away on her kept-fellow what she obtained from … him who kept her.
1863. Reade, Hard Cash, III. 66. The keeperesses eclipsed the keepers in cruelty to the poorer patients.
