Hit big wave, getting scab (13)
I believe the answer is:
strikebreaker
'scab' is the definition.
(I know that scab can be written as strikebreaker)
'hit big wave getting' is the wordplay.
'hit' becomes 'strike' (synonyms).
'big wave' becomes 'breaker' (a breaker is a powerful sea wave).
'getting' says to put letters next to each other.
'strike'+'breaker'='STRIKEBREAKER'
(Other definitions for strikebreaker that I've seen before include "Blackleg" , "Scab" , "One won't come out" .)