It will smooth out the wave (6)
I believe the answer is:
roller
'the wave' is the definition.
(roller is a kind of wave)
'it will smooth' is the wordplay.
I cannot really see how this works, but
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is present in the answer.
'will' could be 'll' (contracted form, as in 'he'll' - 'he will') and 'll' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
'out' acts as a link.
Can you help me to learn more?
(Other definitions for roller that I've seen before include "Bright bird; cylinder" , "Swelling wave; bird" , "Wave; castor; cylinder" , "luxury car?" , "Big wave or hair setter" .)