Infective (6)
I believe the answer is:
septic
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">infective</span>' is the definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for septic that I've seen before include "Putrefactive" , "Poisonous" , "Of wound, infected and pus-filled" , "Putrid" , "Of wound, forming pus" .)