Speed, pace (5)
I believe the answer is:
tempo
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">speed</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">pace</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that pace can be written as tempo)</span><br/ ><br/ ></span>
(Other definitions for tempo that I've seen before include "Speed of 3A" , "Cadence" , "Musical beat or rhythm" , "Rhythm, metre" , "Speed at which piece of music is played" .)