Deity in charge of alarm (5)
I believe the answer is:
panic
'alarm' is the definition.
(alarm can mean panic or worry)
'deity in charge' is the wordplay.
'deity' becomes 'pan' (Pan is an example).
'in charge' becomes 'ic' (abbreviation for 'in charge').
'pan'+'ic'='PANIC'
'of' is the link.
(Other definitions for panic that I've seen before include "Widespread fear" , "Grass" , "Blind fear" , "Losing one's head" , "Lose the head, yield to fear" .)