Cricketer seen with church group (5)
I believe the answer is:
batch
'group' is the definition.
(a batch is a group or set)
'cricketer seen with church' is the wordplay.
'cricketer' becomes 'bat' (batsman).
'seen with' means one lot of letters go next to another.
'church' becomes 'ch' (common abbreviation).
'bat'+'ch'='BATCH'
(Other definitions for batch that I've seen before include "All the bread produced at one baking" , "Arrange things in groups" , "Group of items (as handled)" , "Group of objects prepared or sent together" , "Aggregation" .)