'insomniac' definitions:

Definition of 'insomniac'

From: WordNet
adjective
Experiencing or accompanied by sleeplessness; "insomniac old people"; "insomniac nights"; "lay sleepless all night"; "twenty watchful, weary, tedious nights"- Shakespeare [syn: insomniac, sleepless, watchful]
noun
Someone who cannot sleep [syn: insomniac, sleepless person]

Synonyms of 'insomniac'

From: Moby Thesaurus