Our species (4,7)
I believe the answer is:
homo sapiens
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">our species</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 homo sapiens that I've seen before include "Relative of 1 across" , "Human species" , "Modern humans" , "The one existing species of Man" .)