Think ahead (4)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">think ahead</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for plan that I've seen before include "Scale drawing; scheme" , "propose" , "chart" , "Detailed proposal" , "Method laid out for accomplishing something" .)