French priest's regular contributions to war babies (4)
I believe the answer is:
abbe
'french priest's' is the definition.
(I've seen this before)
'regular contributions to war babies' is the wordplay.
'regular contributions to' means one should take alternating letters.
'war'+'babies'='warbabies'
The alternate letters of 'warbabies' are 'ABBE'.
(Other definitions for abbe that I've seen before include "French clergyman" , "cleric in Paris" , "Continental priest" , "French abbot" , "French cleric" .)