Tread lightly (6)
I believe the answer is:
tiptoe
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tread lightly</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 tiptoe that I've seen before include "Lightly pad" , "Walk quietly on the balls of one's feet" , "or get a bit higher on this?" , "go quietly" , "Go carefully" .)