Deserve minor eyebrow raise at first — it’s needed (5)
I believe the answer is:
merit
'deserve' is the definition.
(I know that deserve can be written as merit)
'minor eyebrow raise at first it's needed' is the wordplay.
'minor' becomes 'mit' (I am not sure about this - if you are sure you should believe this answer much more).
'at first' indicates taking the first letters.
'it's needed' indicates putting letters inside.
The initial letters of 'eyebrow raise' is 'er'.
'mit' enclosing 'er' is 'MERIT'.
Can you help me to learn more?
(Other definitions for merit that I've seen before include "Excellence, worth" , "Earn" , "Deserve; excellence" , "Excellence that deserves to be honoured" , "Goodness" .)