Old Hindu in a jiffy? (4)
I believe the answer is:
jain
'old hindu in a jiffy?' is the definition.
I can't tell whether this definition defines the answer.
'old hindu in' is the wordplay.
'old hindu' becomes 'ja' (I can't explain this - if you can you should give a lot more credence to this answer).
'ja'+'in'='JAIN'
Can you help me to learn more?
(Other definitions for jain that I've seen before include "Member of Indian sect" , "religious Indian" , "Follower of an Indian religion" , "adherent of an Indian religion" .)