Rise or fall of sea waves (4)
I believe the answer is:
tide
(Other definitions for tide that I've seen before include "Season; current" , "Surge of events" , "Ebb and flow of the sea" , "Regular movement" , "Periodic rise and fall of the sea" .)
I believe the answer is:
tide
(Other definitions for tide that I've seen before include "Season; current" , "Surge of events" , "Ebb and flow of the sea" , "Regular movement" , "Periodic rise and fall of the sea" .)