acrophobe (n.)

"morbid fear of heights," 1887, medical Latin, from Greek akros "at the end, topmost" (from PIE root *ak- "be sharp, rise (out) to a point, pierce") + -phobia "fear." Coined by Italian physician Dr. Andrea Verga in a paper describing the condition, from which Verga himself suffered.

In this paper, read somewhat over a year ago at the congress of alienists at Pavia, the author makes confession of his own extreme dread of high places. Though fearless of the contagion of cholera, he has palpitations on mounting a step-ladder, finds it unpleasant to ride on the top of a coach or to look out of even a first-story window, and has never used an elevator. [abstract of Verga's report in American Journal of Psychology, November 1888]

word-forming element meaning "one who dreads, fears, or hates," from French -phobe, from Latin -phobus, from Greek -phobos "fearing," from phobos "fear, panic, flight," phobein "put to flight, frighten" (see phobia).