Bar journey into interior of quarter (6)
I believe the answer is:
stripe
'bar' is the definition.
(I've seen this before)
'journey into interior of quarter' is the wordplay.
'journey' becomes 'trip' (trip is a kind of journey).
'into' indicates putting letters inside.
'interior of quarter' becomes 'se' (I can't explain this - if you can you should give a lot more credence to this answer).
'trip' going inside 'se' is 'STRIPE'.
Can you help me to learn more?
(Other definitions for stripe that I've seen before include "Chevron; band" , "Military sign of rank" , "Chevron indicating rank" , "promotion, maybe" , "Priest (anag)" .)