Duck — explorer (5)
I believe the answer is:
drake
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">duck</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(drake is a male duck)</span><br/ ><br/ >'<span class="explanation-format__original">explorer</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that Drake is a navigator)</span><br/ ><br/ ></span>
(Other definitions for drake that I've seen before include "Male water-bird" , "Nick" , "Elizabethan sailor" , "sea captain" , "world traveller" .)