Bodybuilders pump it (4)
I believe the answer is:
iron
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">bodybuilders pump it</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for iron that I've seen before include "Smoother - metal" , "Press clothes" , "Fe - golf club" , "Decrease" , "Smooth things" .)