Promenade amongst the biggest rollers (6)
I believe the answer is:
stroll
'promenade' is the definition.
(I know that promenade can be written as stroll)
'amongst the biggest rollers' is the wordplay.
'amongst' indicates a hidden word.
'STROLL' is hidden within 'biggest rollers'.
(Other definitions for stroll that I've seen before include "Promenade" , "A pleasant and leisurely walk" , "swan" , "A quiet, pleasant walk" , "A casual or lazy walk" .)