Special anniversary (7)
I believe the answer is:
jubilee
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">special anniversary</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 jubilee that I've seen before include "Clip, say" , "Sort of clip" , "SECOND PART OF 15" , "Celebration of 50th year" , "period of rejoicing" .)