Cud-chewing animal (8)
I believe the answer is:
ruminant
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">cud-chewing animal</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 ruminant that I've seen before include "Cud chewer" , "Animal chewing cud" , "One chews the cud" , "contemplating" , "Eg, sheep, giraffe, cow" .)