All set (5)
I believe the answer is:
ready
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">all set</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for ready that I've seen before include "Prompt and adequate" , "Willing (to do something), prepare" , "Prepare money" , "Intelligent" , "Cash; within reach" .)