Quell, as concerns (5)
I believe the answer is:
allay
'quell as concerns' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for allay that I've seen before include "Quell" , "Calm fears" , "Alleviate (hunger)" , "Mitigate" , "Calm, put at rest" .)