Serve, wait upon (6)
I believe the answer is:
attend
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">serve</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that serve can be written as attend)</span><br/ ><br/ >'<span class="explanation-format__original">wait upon</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ ></span>
(Other definitions for attend that I've seen before include "Wait upon or be present" , "Be present at, or accompany" , "Pay heed" , "Go regularly to, church perhaps" , "Be present at, say meeting" .)