Fess up (to) (5)
I believe the answer is:
admit
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">fess up to</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 admit that I've seen before include "permit to come in" , "Usher in" , "Confess; allow in" , "Grant entry to" , "Let in - concede" .)