Eat grass in a field (5)
I believe the answer is:
graze
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">eat grass in a field</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 graze that I've seen before include "as some animals do" , "Eat grass; scrape skin" , "To eat constantly" , "Get one's oats" , "Bark (shin)" .)