Word meaning the opposite (7)
I believe the answer is:
antonym
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">word meaning the opposite</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for antonym that I've seen before include "as host is for guest, eg" , "something completely different" , "opposing term" , "As 'happy' is to 'sad' or 'long' to 'short'" , "A word opposite in meaning to another" .)