Present occasion (5)
I believe the answer is:
nonce
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">present occasion</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 nonce that I've seen before include "One serving prison sentence" , "The present time" , "The moment" , "what you may call a one-off" , "particular occasion" .)