acrophobe
/ˈækrəˌfoʊb/
noun
- A person who has an extreme or irrational fear of heights.
- He knew he was an acrophobe when his hands started shaking on the observation deck.
- The tour guide was patient with the acrophobe in the group, offering to take a different route.
- As an acrophobe, she could not even stand on a step stool without feeling dizzy.