Be disloyal to (6)

I believe the answer is:
betray
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">be disloyal to</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for betray that I've seen before include "Sell down the river" , "Hand someone over to an enemy" , "Give away" , "Inadvertently reveal" , "Inform on (someone)" .)