incubus

Definition of Incubus in English :

1. incubus

a male demon believed to lie on sleeping persons and to have sexual intercourse with sleeping women

2. incubus, nightmare

a situation resembling a terrifying dream

3. incubus

someone who depresses or worries others

WordNet Lexical Database for English. Princeton University. 2010.

Incubus

noun plural -bi (-ˌbaɪ) or -buses

1.

a demon believed in folklore to lie upon sleeping persons, esp to have sexual intercourse with sleeping women

Compare succubus

2.

something that oppresses, worries, or disturbs greatly, esp a nightmare or obsession

nounWord forms: plural ˈincubuses or ˈincuˌbi (ˈɪnkjuˌbaɪ ; inˈkyo̅obīˌ; ˈɪŋkjuˌbaɪ ; iŋˈkyo̅obīˌ; ˈɪnkjəˌbaɪ ; inˈkyəbīˌ; ˈɪŋkjəˌbaɪ ; iŋˈkyəbīˌ)

1.

an evil spirit or demon thought in medieval times to descend upon and have sexual intercourse with women

n. pl. in·cu·bus·es or in·cu·bi (-bī′)

1. An evil spirit supposed to descend upon and have sexual intercourse with women as they sleep.

2. A nightmare.

3. An oppressive or nightmarish burden.