Barely make do, with "by" (3)
I believe the answer is:
eke
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">barely make do with by</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for eke that I've seen before include "Make a laborious living" , "Increase, lengthen" , "Make a living laboriously - a palindrome" , "long ago" , "Supplement" .)