Afear becomes a(n) when a situation becomes so dreaded that a person goes to almost any length to avoid it.

Phobia.

Explanation:

Phobia is described as the irrational or obsessive fear or anxiety that an individual faces from a particular thing or situation. It is basically a situational fear in which an individual becomes extremely dreaded and this dread makes them go the length of avoiding it as it then gets converted to a phobia(as a learned response from the experience). These could be caused due to several factors that could be genetic or environmental and fear/anxiety is the prime symptom that the person faces in such a situation.

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