Small flap; computer key (3)
I believe the answer is:
tab
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">small flap</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >'<span class="explanation-format__original">computer key</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that tab is a computer key)</span><br/ ><br/ ></span>
(Other definitions for tab that I've seen before include "Running bar bill" , "Bar tally; small flap" , "Ring pull" , "Small flap - bill" , "Flap; meal bill" .)