Means of control (5)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">means of control</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 reins that I've seen before include "Power to direct and control" , "Checks" , "Means of control for a horse" , "Guiding straps" , "Control for horses" .)
(Other definitions for button that I've seen before include "fast driver?" , "One may invite the press to function" , "Knob for fastening" , "Round fastener" , "Push it or do it up!" .)