Become religious after knocking over veggie (6)
I believe the answer is:
turnip
'veggie' is the definition.
(I know that turnip is a type of veggie)
'become religious after knocking over' is the wordplay.
'become' becomes 'turn' (synonyms).
'religious after knocking over' becomes 'ip' (I can't explain this - if you can you should believe this answer much more).
'turn'+'ip'='TURNIP'
Can you help me to learn more?
(Other definitions for turnip that I've seen before include "Large-rooted vegetable related to the cabbage" , "food item" , "'Root vegetable, yellow or white (6)'" , "Root vegetable of the mustard family" , "Globular food plant" .)