Phrasal verbs related to fear

Fear for 
to be worried about somebody/something
He feared for his mother, left alone on the farm.

Run away from
Try to avoid dealing with a difficult or unpleasant situation. 
You can’t keep running away from the problem.

Scare off
To make a person or animal so scared that they go away. 
 My father installed an alarm system to scare off burglars. 

Believe in 
To be sure something or somebody exists. 
My children still believe in witches and ghosts. 

Pass out
To become unconscious, faint.
Tracy is so scared of mice, she passed out the other day when she saw one in the kitchen.