Rate of progress (5)
I believe the answer is:
speed
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">rate of progress</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 speed that I've seen before include "Dispatch" , "Travel quickly" , "Velocity" , "Move quickly (and illegally?)" , "Expedition" .)