After church I'll relax (5)
I believe the answer is:
'relax' is the definition.
(I've seen this before)
'after church i'll' is the wordplay.
'after' means one lot of letters go next to another.
'church' becomes 'ch' (common abbreviation).
'ch' next to 'ill' is 'CHILL'.
(Other definitions for chill that I've seen before include "This disheartens", "Make cooler", "Iciness", "Cool, coolness", "Slang injunction to relax - it's cold".)