Soldiers take up cricket, say, to catch ball (6)
I believe the answer is:
troops
'soldiers' is the definition.
(a troop is a group of soldiers)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for troops that I've seen before include "Groups of soldiers" , "Bodies of soldiers" , "men" , "Military divisions" , "Cavalry" .)