Busy, busy, busy (2,3,2)
I believe the answer is:
on the go
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">busy busy busy</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 on the go that I've seen before include "Always busy" , "Ever busy" , "Active, in constant motion" , "Very busy, in constant motion" , "Busy and active" .)