acrophobia
noun
ac·ro·pho·bia ˌa-krə-ˈfō-bē-ə 
: abnormal dread of being in a high place : fear of heights
acrophobe
ˈa-krə-ˌfōb
noun acrophobic
ˌa-krə-ˈfō-bik
adjective 
Example Sentences
Recent Examples on the Web The experience catalyzes a quest to understand and overcome her acrophobia. 
Eva Holland, Outside Online, 14 Apr. 2020 Examples: acrophobia, the fear of heights; arachnophobia, the fear of spiders. Kayla Webley Adler, Marie Claire, 8 July 2019 Latest Stories Virtual reality helped people with acrophobia, a fear of heights, overcome their fear and venture onto mountains and rope bridges, researchers said. NBC News, 11 July 2018
Eva Holland, Outside Online, 14 Apr. 2020 Examples: acrophobia, the fear of heights; arachnophobia, the fear of spiders. Kayla Webley Adler, Marie Claire, 8 July 2019 Latest Stories Virtual reality helped people with acrophobia, a fear of heights, overcome their fear and venture onto mountains and rope bridges, researchers said. NBC News, 11 July 2018 Word History
Etymology
borrowed from Italian acrofobia, from acro- acro- + -fobia -phobia
First Known Use
circa 1888, in the meaning defined above
Medical Definition
acrophobia
noun
ac·ro·pho·bia ˌak-rə-ˈfō-bē-ə
: abnormal or pathological dread of being in a high place : fear of heights