Butter or margarine, eg (6)
I believe the answer is:
spread
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">butter</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >'<span class="explanation-format__original">margarine eg</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(margarine is a kind of spread)</span><br/ ><br/ ></span>
(Other definitions for spread that I've seen before include "Land in America" , "expansion?" , "Extend - banquet" , "Disseminate through padres" , "Broaden - drapes (anag)" .)