deep-rooted fear

Translations
глубоко укоренившийся страх
She had a deep-rooted fear of heights that prevented her from attempting rock climbing.
У нее был глубоко укоренившийся страх высоты, который мешал ей пробовать скалолазание.
Definitions
A deep-rooted fear is a strong and persistent feeling of anxiety or dread that has developed over a long period of time, often originating from past experiences or subconscious influences, and is difficult to overcome.