insomniac
1 of 2adjective
in·som·ni·ac in-ˈsäm-nē-ˌak 
: of, relating to, characterized by, or affected with insomnia
insomniac nights
insomniac tendencies
… he lived for several months with an older brother who didn't enforce bedtime rules. Joe started exchanging text messages with an insomniac friend and played online games against opponents on the other side of the planet.
John Cline
John ClineThe last thing my sisters and I would do on Christmas Eve—before retiring to our separate rooms and our private paroxysms of insomniac anticipation—was make sure our parents had put out cookies for Santa Claus. Christopher Caldwell
Christopher Caldwellinsomniac
2 of 2noun
plural insomniacs
: a person affected with insomnia
Many insomniacs develop anxiety about going to bed and they fear sleeplessness, which can worsen insomnia. Andrew Weil
Andrew Weil
Synonyms
Adjective
- awake
- sleepless
- wakeful
- wide-awake
See all Synonyms & Antonyms 
Word History
Etymology
Adjective
from attributive use of insomniac entry 2
Noun
insomnia + -ac
First Known Use
Adjective
1877, in the meaning defined above
Noun
1879, in the meaning defined above
Medical Definition
insomniac 1 of 2
noun
in·som·ni·ac -nē-ˌak
: one affected with insomnia
insomniac
2 of 2adjective
: affected with insomnia
an insomniac patient
insomniacs
noun
as in wakers
Synonyms & Similar Words
Relevance
- wakers
- risers
Antonyms & Near Antonyms
- sleepers
- slumberers
- dozers
- nodders
- centigrade
- centigrades
- centigram
- centigramme
- centigrammes
- centigrams
- centile
- centiles
- centiliter
- centiliters
- centilitre
- centilitres
- centillion
- centillions
- centillionths
- centim
- centime
- centimes
- centimeter
- centimeter dyne
- centimeter-gram-second
- centimeters
- centimetre
- centimetre-gram-second
- centimetre-gramme-second