Reluctance to move (7)
I believe the answer is:
inertia
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">reluctance to move</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for inertia that I've seen before include "'Sluggishness, indolence (7)'" , "Tendency to inactivity" , "Slowness to act, lassitude" , "lack of action" , "Lack of movement" .)