More enthusiastic mourner (6)
I believe the answer is:
keener
This clue is a double definition.
'more enthusiastic' is the first definition.
(I've seen this before)
'mourner' is the second definition.
(keen can mean to cry or lament)
(Other definitions for keener that I've seen before include "More eager - mourner" , "more piercing" , "More eager; one lamenting" , "person mourning" , "More devoted" .)