Wave's high point (5)
I believe the answer is:
crest
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">wave's high point</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for crest that I've seen before include "Head" , "Peak - comb" , "Surmount" , "Heraldic device representing a family" , "top position" .)