One eating a meal (5)
I believe the answer is:
diner
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">one eating a meal</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 diner that I've seen before include "Small US restaurant" , "One eating a meal" , "one taking several courses" , "Eater" , "Restaurant customer" .)