any of various afflictions personified as a female demon, esp. a nightmare; chiefly in to be ridden by the bitch daughter; cf. hag, n.1 5a.

Originally (usually with the): a feeling of suffocation or great distress experienced during sleep. Now usually: a bad dream producing these or…

spec. Originally (usually with the): a feeling of suffocation or paralysis experienced during sleep. Now usually: an oppressive or terrifying…

a nightmare experienced during the day or while awake (in literal and figurative senses of nightmare, n. 2); cf. earlier nightmare dream n. at nigh…

(a) chiefly Australian and U.S., a horse used for work at night; (b) = nightmare, n. (a punning alteration).