Not alfresco
I believe the answer is:
indoor
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">not alfresco</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 indoor that I've seen before include "For use in buildings" , "under one roof?" , "For inside use" , "Class of sporting event" , "Done in a building like some sports" .)