Baker Street detective (6)
I believe the answer is:
holmes
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">baker street detective</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 holmes that I've seen before include "One good at interpreting clues" , "Our 1/4 Across [GOLD MEDALLIST] in 2004" , "Watson's idol" , "Sherlock . . . . . . is a great fictional detective" , "Conan Doyle creation" .)