*hypochondriasis*

n. [ NL. So named because supposed to have its seat in the hypochondriac regions. See Hypochondriac, Hypochondrium, and cf. Hyp, 1st Hypo. ] (Med.) A mental disorder in which melancholy and gloomy views torment the affected person, particularly concerning his own health; a morbid and deluded belief that one is afflicted with disease.
Syn. -- hypochondria. [ 1913 Webster ]