Minnaloushe was
Iseult Gonne's cat (the daughter of Yeats' unrequited love,
Maud Gonne.) I've never been able to find an explanation for the name's meaning, and I don't think it's an Irish word. The best I've been able to figure is this (and this is theory)--- In
German, "minna" means protective, and loushe is pretty close to the sound of the word for "light" in latin (lux, lucis). So I think that Minnaloushe may mean "protective light," which certainly goes with the moon image in "The Cat and the Moon," and the idea that Gonne and Yeats would have viewed Minnaloushe as a familiar.