Panic room's evacuation after arriving first (5)
I believe the answer is:
alarm
'panic' is the definition.
(alarm can mean panic or fear)
'room's evacuation after arriving first' is the wordplay.
I cannot quite understand how this works, but
'after' could be 'ala' ('a la' - 'in the style of ' or 'after' in French) and 'ala' is located in the answer.
'room' could be 'rm' (abbreviation) and 'rm' is located in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for alarm that I've seen before include "Device signalling danger" , "Device to signal danger" , "Clock that wakes the sleeper" , "Feeling of fear" , "Warning sound or signal" .)