insomnia

[in-som-nee-uh] /ɪnˈsɒm ni ə/
noun
1.
inability to obtain sufficient sleep, especially when chronic; difficulty in falling or staying asleep; sleeplessness.
Origin
1685-95; < Latin, equivalent to insomn(is) sleepless (in- in-3 + somn(us) sleep + -is adj. suffix) + -ia -ia
Related forms
insomnious, adjective
British Dictionary definitions for insomnia

insomnia

/ɪnˈsɒmnɪə/
noun
1.
chronic inability to fall asleep or to enjoy uninterrupted sleep related adjective agrypnotic
Derived Forms
insomnious, adjective
Word Origin
C18: from Latin, from insomnis sleepless, from somnus sleep
Word Origin and History for insomnia
n.

1620s, insomnie, from Latin insomnia "want of sleep," from insomnis "sleepless," from in- "not" (see in- (1)) + somnus "sleep" (see Somnus). The modern form is from 1758.

insomnia in Medicine

insomnia in·som·ni·a (ĭn-sŏm'nē-ə)
n.
Chronic inability to fall asleep or remain asleep for an adequate length of time.

insomnia in Science
insomnia
  (ĭn-sŏm'nē-ə)   
Chronic inability to fall asleep or remain asleep for an adequate length of time.
insomnia in Culture
insomnia [(in-som-nee-uh)]

A persistent and prolonged inability to sleep.