Male domestic feline (6)
I believe the answer is:
tomcat
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">male domestic feline</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 tomcat that I've seen before include "Asparagus, perhaps" , "Domestic male feline" , "Male moggie" , "Male pet" , "Male animal: US Navy fighter plane" .)