Social function (4)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">social function</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for ball that I've seen before include "Sphere for sport" , "Sphere - dance" , "Party" , "Round object - dance" , "form of entertainment" .)
(Other definitions for reception that I've seen before include "Entrance for office" , "First class" , "Hotel entrance area" , "A social event" , "signal quality" .)