Make beloved friend earnest in part (6)
I believe the answer is:
endear
'make beloved' is the definition.
(I've seen this before)
'friend earnest in part' is the wordplay.
'in part' indicates the answer is hidden within the clue.
'ENDEAR' is hidden in the letters of 'friend earnest'.
(Other definitions for endear that I've seen before include "Cause to be beloved" , "Attract" , "Make lovable or please" , "Delight - please" , "Inspire affection" .)