The Britannica Dictionary
mobile search
Home
Ask the Editor
Word of the Day
Quizzes
Core Vocabulary
Browse the Dictionary
×
Britannica Homepage
Ask the Editor
Word of the Day
Quizzes
Core Vocabulary
Browse the Dictionary
The Britannica Dictionary
sleepless
1 ENTRIES FOUND:
sleepless
(adjective)
sleepless
/
ˈ
sliːpləs/
adjective
sleepless
/
ˈ
sliːpləs/
adjective
Britannica Dictionary definition of SLEEPLESS
1
always used before a noun
:
without sleep
a
sleepless
night
[+] more examples
[-] hide examples
[+] Example sentences
[-] Hide examples
2
not used before a noun
:
not able to sleep
He lay
sleepless
in bed.
[+] more examples
[-] hide examples
[+] Example sentences
[-] Hide examples
— sleeplessly
adverb
He lay
sleeplessly
.
[+] more examples
[-] hide examples
[+] Example sentences
[-] Hide examples
— sleeplessness
noun
[
noncount
]
He suffers from
sleeplessness
. [=
insomnia
]
[+] more examples
[-] hide examples
[+] Example sentences
[-] Hide examples
ASK THE EDITOR
What are the plural forms of
check-in
,
passerby
, and
spoonful
?
See the answer »
QUIZZES
Vocabulary Quiz
Test your word power
Take the Quiz »
Name That Thing
Take our visual quiz
Test Your Knowledge »
WORD OF THE DAY
expensive
:
costing a lot of money
Learn More »