agoraphobia

n. abnormal fear of open spaces (Psychiatry)

Agoraphobia is an anxiety disorder which primarily consists of the fear of certain settings that may present unexpected challenges or demands. These could include parking lots, shoppings malls or restaurants. The social consequences of having a panic attack or losing control in public often becomes an additional source of fear in its own right. As a result, severe sufferers of agoraphobia may become confined to their homes, experiencing difficulty traveling from this "safe place."
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The word agoraphobia is derived from Greek words literally meaning "fear of the marketplace. [more]Agoraphobia - Community and Resources

Noun
1. a morbid fear of open spaces (as fear of being caught alone in some public place)
(hypernym) phobia, phobic disorder, phobic neurosis

noun
fear of being in open spaces