Ladder steps (5)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">ladder steps</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 rungs that I've seen before include "Ladder parts" , "bars" , "Crosspieces of a ladder" , "Steps of a ladder" .)