(Science: psychology) A persistent, irrational, intense fear of a specific object, activity or situation (the phobic stimulus), fear that is recognised as being excessive or unreasonable by the individual himself.
When a phobia is a significant source of distress or interferes with social functioning, it is considered a mental disorder, phobic disorder (or neurosis). In DSM III phobic disorders are subclassified as agoraphobia, social phobias and simple phobias. Used as a word termination denoting irrational fear of or aversion to the subject indicated by the stem to which it is affixed.
Origin: Gr. Phobos = fear