Swell, general waves (7)
I believe the answer is:
enlarge
'swell' is the definition.
(thesaurus)
'general waves' is the wordplay.
'waves' is an anagram indicator.
'general' with letters rearranged gives 'ENLARGE'.
(Other definitions for enlarge that I've seen before include "Make bigger, say photo" , "Make greater" , "go into greater detail" , "swell?" , "Increase in size" .)