Some time ago (4)
I believe the answer is:
once
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">some time ago</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 once that I've seen before include "Formerly; as soon as" , "in days of yore?" , "On one occasion" , "Formerly - not repeated" , "Just as a single occurrence" .)