Perfidious (9)
I believe the answer is:
dishonest
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">perfidious</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 dishonest that I've seen before include "Untrustworthy" , "Deceitful - hedonists (anag)" , "Insincere" , "shady" , "shifty" .)