Like preparing endlessly (4)
I believe the answer is:
akin
'like' is the definition.
(I've seen this before)
'preparing endlessly' is the wordplay.
'preparing' becomes 'making' ('make' can be a synonym of 'prepare').
'endlessly' indicates the central letters (the ends of the words are removed).
The middle letters of 'making' are 'AKIN'.
(Other definitions for akin that I've seen before include "Of similar character" , "Similar, like" , "Related or similiar" , "Seemingly related" , "Related by blood" .)