Play dishonestly (5)
I believe the answer is:
cheat
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">play dishonestly</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 cheat that I've seen before include "Deceive, defraud" , "Take unfair advantage of" , "One dealing dishonestly" , "Two-timer" , "Play dishonestly" .)