the GNU version of the Collaborative International Dictionary of English
noun.
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.
noun.
A mental disorder characterized by excessive fear of or preoccupation with a serious illness, despite medical testing and reassurance to the contrary.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
noun.
chronic and abnormal anxiety about imaginary symptoms and ailments
Word Usage
"Fortunate that it was so, otherwise a lunatic asylum, or a permanent state of what the doctors call hypochondriasis, might have followed."