Elbow grease (6)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">elbow grease</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that elbow grease can be written as effort)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for effort that I've seen before include "Vigorous attempt" , "Strenuous exertion" , "'Endeavour, exertion (6)'" , "For eft (anag.)" , "Hard mental or physical work" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">elbow grease</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that elbow grease can be written as exertion)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for exertion that I've seen before include "labour" , "Tire oxen with heavy effort" , "Physical or mental effort" , "Use of physical energy" , "Great effort" .)