Longman Dictionary of Contemporary English
Wiktionary
n. female housemaster
Usage examples of "housemistress".
As they left, with all the girls surreptitiously gazing out of the window to catch a glimpse of Declan, Maud did nothing to endear herself to Caitlin's housemistress by calling out, 'Don't worry, Caitlin darling, you can always leave if you don't like it.
How she was always climbing out of her dormitory window at night and running off to a night-club called Gaslight, and how Miss Fagan, their housemistress who was always pinging bras, far from being furious, looked really excited when Flora streaked through the house for a bet, and how Flora passed her French oral.
One by one she relived them: one a mere interview with a scientist, another a spell as housemistress to an outpost halfway across the Earth-Sphere of colonization, keeping the normals sane.