Minute hands, essentially (5)
I believe the answer is:
radii
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">minute hands essentially</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for radii that I've seen before include "Two making up diameter" , "Halves of diameter" , "Lines from centre to perimeter of a circle" , "Lines from the centre to the circumference of a circle" , "Veins of insect's wings" .)