"Clunk!" (4)
I believe the answer is:
thud
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">clunk</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that clunk can be written as thud)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for thud that I've seen before include "Dull sound made by a falling body" , "Dull, heavy sound" , "Noise of dull impact" , "Dull heavy impact" , "Clonk" .)