Bertrand —, philosopher (7)
I believe the answer is:
russell
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">bertrand</span>' is the first definition.<br/ ><br/ >'<span class="explanation-format__original">philosopher</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(Bertrand Russell)</span><br/ ><br/ ></span>
(Other definitions for russell that I've seen before include "Brand" , "actress (Rosalind or Jane)" , "...another one [PHILOSOPHER]" , "Jane -, US actress" , "group of universities" .)