Eg, wheat (5)
I believe the answer is:
grain
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">eg wheat</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that wheat is a type of grain)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for grain that I've seen before include "Pattern of lines in wood" , "Character" , "basis for whisky" , "Small particle - wood texture" , "Cereal crops" .)