Causes concern (6)
I believe the answer is:
alarms
'causes concern' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for alarms that I've seen before include "Danger signals" , "rattles" , "Warning clocks that wake us up" , "Alerting devices - burglars?" , "Fills with apprehension" .)