Afoot (5)
I believe the answer is:
astir
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">afoot</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for astir that I've seen before include "Out of bed or on the move" , "Excitedly moving" , "Up and about -- is art (anag)" , "Busy" , "Starting to move" .)