Way up (or down) (5)
I believe the answer is:
stair
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">way up or down</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 stair that I've seen before include "Support on which to step" , "One step in a series" , "something of a case" , "one on the way up" , "One step of a flight" .)