insomniac
/ɪnsɒmˈniːæk/Definitions
1. noun
A person who suffers from insomnia, or the inability to sleep.
“After months of struggling with insomnia, Sarah became an insomniac, unable to get more than a few hours of sleep each night.”
2. adjective
Relating to or characteristic of insomnia.
“The insomniac patient was prescribed medication to help regulate their sleep patterns.”