Insomniac

Pronunciation: /ˌɪnˈsɑːmniːˌæk/

Insomniac (noun)

  1. A person who often cannot sleep or stays awake for a long time at night.
  2. Someone with a continuing problem of not being able to fall asleep or stay asleep.

Examples

  • An insomniac often stays awake long after midnight.
  • The insomniac feels tired but can’t fall asleep.