Abut on (6)
I believe the answer is:
adjoin
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">abut on</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for adjoin that I've seen before include "Meet - touch" , "Interconnect" , "Be next to (something)" , "20 down" , "Be next or nearest to" .)