\Hy`po*chon"dri*a*sis\, 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.