Breach of faith (8)
I believe the answer is:
betrayal
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">breach of faith</span>' is the definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for betrayal that I've seen before include "Breach of trust" , "Act of disloyalty" , "sale" , "The crime of Judas" , "Double-crossing" .)