Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “nightmare”

nightmare

noun [C] uk   /ˈnaɪt.meər/ us    /-mer/
B1 a very upsetting or frightening dream: a terrifying nightmare I shouldn't have watched that movie - it'll give me nightmares. B1 an extremely unpleasant event or experience or possible event or experience: The whole journey was a nightmare - we lost our luggage and we arrived two days late. Being trapped underwater is my worst nightmare.
nightmarish
adjective uk   /-meə.rɪʃ/ us    /-mer.ɪʃ/
nightmarishly
adverb uk   /-meə.rɪʃ.li/ us    /-mer.ɪʃ.li/
(Definition of nightmare from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
What is the pronunciation of nightmare?
Browse related topics

You are looking at an entry to do with Difficult situations and unpleasant experiences, but you might be interested in these topics from the Easy and difficult topic area:

Add Cambridge dictionaries to your browser to your website

Definitions of “nightmare” in other dictionaries

Word of the Day

initial

of or at the beginning

Word of the Day

Come on – you can do it! Phrasal verbs with ‘come’.

by Liz Walter​,
November 19, 2014
As part of an occasional series on the tricky subject of phrasal verbs, this blog looks at ones formed with the verb ‘come’. If you are reading this blog, I’m sure you already know come from, as it is one of the first things you learn in class: I come from Scotland/Spain.

Read More 

ped-text verb

November 24, 2014
to text someone while walking I’m ped-texting, I’m looking down at my phone, 75 percent of the time.

Read More