Gazelle or impala, eg (8)
I believe the answer is:
antelope
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">gazelle</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">impala eg</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(impala is a kind of antelope)</span><br/ ><br/ ></span>
(Other definitions for antelope that I've seen before include "Hoofed mammal" , "Hartebeest, perhaps" , "One leapt badly on the graceful animal" , "Eg, gazelle or gnu" , "bounder!" .)