Eldest of the Baldwin brothers
I believe the answer is:
alec
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">eldest of the baldwin brothers</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 alec that I've seen before include "A smart . . . . is a know-all in lace" , "Actor Guinness is smart" , "Sir - Douglas-Home, former PM" , "Smart man?" , "Guinness (a smart lad?)" .)