Floorboard sound
I believe the answer is:
creak
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">floorboard sound</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for creak that I've seen before include "Audibly reveal weakness under strain" , "Unoiled hinge sound" , "Harsh squeaking noise" , "harsh squeal" , "Squeaking sound" .)