Synonyms of 'sleepless'
1 wakefulDictionary, disturbed, restless
I have sleepless nights worrying about her.
2 alertDictionary, vigilant, watchful
his sleepless vigilance
Copyright © 2016 by HarperCollins Publishers. All rights reserved.
If you are alert, you are paying full attention to things around you and are able to deal with anything that might happen.
He had been spotted by an alert neighbour.
If you have a restless night, you do not sleep properly and when you wake up you feel tired and uncomfortable.
He had spent a restless few hours on the plane.
Someone who is vigilant gives careful attention to a particular problem or situation and concentrates on noticing any danger or trouble that there might be.
Police warned the public to be vigilant and report anything suspicious.
Thesaurus for sleepless from the Collins English Thesaurus
A sleepless night is one during which you do not sleep.