Suddenly frighten fryer in charge (5)
I believe the answer is:
panic
'suddenly frighten' is the definition.
(I know that to panic someone is to frighten them suddenly)
'fryer in charge' is the wordplay.
'fryer' becomes 'pan' (frying pan).
'in charge' becomes 'ic' (abbreviation for 'in charge').
'pan'+'ic'='PANIC'
(Other definitions for panic that I've seen before include "Contagious fear" , "Widespread fear" , "Lose one's nerve" , "Frantic fright" , "State of overwhelming fear" .)