[in.som.nia] n [L, fr. insomnis sleepless, fr. in- + somnus sleep--more at somnolent] (ca. 1623): prolonged and usu. abnormal inability to obtain adequate sleep -- in.som.ni.ac adj or n
INSOMNIA
Meaning of INSOMNIA in English
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012