Perspire (5)
I believe the answer is:
sweat
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">perspire</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for sweat that I've seen before include "It's hard work" , "Trouble in Australia" , "Male perspiration?" , "Perspire" , "Waste (anag.)" .)