Adjoin at one end (4)
I believe the answer is:
abut
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">adjoin at one end</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 abut that I've seen before include "Of building or land, end or lean against" , "Impinge" , "Meet" , "Adjoin at one end" , "Touch, lean on" .)