ATM opening
I believe the answer is:
slot
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">atm opening</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 slot that I've seen before include "Opening for coin or TV programme" , "Opening (for coins)" , "Narrow opening as in gaming machine" , "Space for coin or programme" , "Fit into puzzle" .)