fear of falling from a high place
<psychology> Morbid fear of deep places or of looking into them. ... Origin: G. Bathos, depth, + phobos, fear ... (05 Mar 2000) ... 
Type: Term Pronunciation: bath′ō-fō′bē-ă Definitions: 1. Morbid fear of deep places or of looking into them.
Bathophobia: An abnormal and persistent fear of depths. Sufferers from bathophobia experience anxiety even though they realize they are safe from falling into or being consumed by depths. The feared object may be a long, dark hallway, a well or a deep pool or lake. 'Bathophobia' is derived from the Greek 'bathos' (depth) and 'phobos' (fear).
Bathophobia is the fear of depth.
bathophobia A fear of depths or of descending into depths; such as, occurs occurs when looking down into a well or when going down into a body of water in a submarine.