First Known Use: 14th century
Dictionary
nightmare
noun night·mare \ˈnīt-ˌmer\
: a dream that frightens a sleeping person : a very bad dream
: a very bad or frightening experience or situation
Full Definition of NIGHTMARE
1
: an evil spirit formerly thought to oppress people during sleep
2
: a frightening dream that usually awakens the sleeper
3
: something (as an experience, situation, or object) having the monstrous character of a nightmare or producing a feeling of anxiety or terror
— nightmare adjective
— night·mar·ish \-ˌmer-ish\ adjective
— night·mar·ish·ly adverb
See nightmare defined for English-language learners
See nightmare defined for kids
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Origin of NIGHTMARE
Middle English, from 1night + 1mare
Related to NIGHTMARE
Rhymes with NIGHTMARE
affair, aglare, airfare, Ajmer, Altair, antbear, armchair, au pair, aware, bakeware, barware, Basseterre, Baudelaire, beachwear, bergère, beware, bid fair, big hair, black bear, bricklayer, broodmare, brown bear, bugbear, caneware, carfare, Carrère, cave bear, chi-square, clayware, club chair, compare, compere, confrere, cookware, corsair, courseware, creamware, crosshair, cudbear, daymare, dead air, decare, deck chair, declare, delftware, despair, dishware, éclair, elsewhere, ensnare, eyewear, fanfare, fieldfare, firmware, flatware, Flaubert, footwear, forbear, forebear, forswear, foursquare, freeware, funfair, galère, giftware, glassware, Great Bear, groupware, Gruyère, guard hair, hardware, health care, hectare, high chair, horsehair, hot air, impair, infare, Khmer, Kildare, knitwear, life-care, light air, longhair, loungewear, Mayfair, menswear, meunière, midair, mohair, Molière, neckwear, no fair, outstare, out-there, outwear, playwear, plein air, plowshare, Poor Clare, Port Blair, portiere, premiere, prepare, pushchair, rainwear, redware, repair, root hair, Sancerre, sea hare, shank's mare, shareware, shorthair, side chair, Sinclair, skiwear, sleepwear, slipware, sloth bear, software, somewhere, spongeware, sportswear, stemware, stoneware, sun bear, swimwear, threadbare, tinware, torchère, trouvère, tuyere, unfair, unhair, unswear, Voltaire, warfare, welfare, wheelchair, wirehair, workfare
NIGHTMARE Defined for Kids
nightmare
noun night·mare \ˈnīt-ˌmer\
Definition of NIGHTMARE for Kids
1
: a frightening dream
2
: a horrible experience
— night·mar·ish \ˈnīt-ˌmer-ish\ adjective
Word History of NIGHTMARE
The -mare in nightmare comes from an Old English word for a kind of evil spirit. Such spirits were believed to bother people who were sleeping.
Medical Dictionary
nightmare
noun night·mare \ˈnīt-ˌma(ə)r, -ˌme(ə)r\
Medical Definition of NIGHTMARE
: a frightening or distressing dream that usually awakens the sleeper
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