Meaning & Definition
adjective
Unable to sleep; characterized by a lack of sleep.
After the stressful week, I found myself feeling completely sleepless.
Not affording sleep; often used to describe nights spent awake.
The sleepless night before the exam left me exhausted.
Causing or resulting in a lack of sleep.
The baby’s sleepless cries kept the entire household awake.
Etymology
Old English 'slepian' meaning 'to sleep' + '-less' meaning 'without'.
Common Phrases and Expressions
sleepless nights:
nights spent without sleep, often due to worry or excitement.
sleepless in Seattle:
a reference to a famous romantic film depicting longings and sleeplessness.
sleeplessness:
the condition of being unable to sleep.
Slang Meanings
Zombie mode
After two days of no sleep, I felt like I was in zombie mode.
Burning the midnight oil
She was burning the midnight oil to finish her project.