Scratch (out) (3)
I believe the answer is:
'scratch out' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for eke that I've seen before include "Make a living laboriously - a palindrome" , "addition to Scots" , "To -- something out is to make it go further" , "Make last longer" , "Make a laborious living" .)