Beat anxiety (6)
I believe the answer is:
stress
I believe this clue is a double definition.
'beat' is the first definition.
(I've seen this in another clue)
'anxiety' is the second definition.
(anxiety is stress or tension)
(Other definitions for stress that I've seen before include "Emphasise the strain" , "Lay emphasis on - it's a strain" , "Dwell on" , "what causes tension" , "result of being overworked" .)