Attending Oxford maybe Ruth becomes arrogant (6)
I believe the answer is:
uppity
'arrogant' is the definition.
(I've seen this before)
'attending oxford maybe ruth' is the wordplay.
'attending oxford maybe' becomes 'up' (I can't explain this - if you can you should give a lot more credence to this answer).
'ruth' becomes 'pity' (synonyms).
'up'+'pity'='UPPITY'
'becomes' is the link.
Can you help me to learn more?
(Other definitions for uppity that I've seen before include "Pert; haughty" , "Presumptuously arrogant" , "Needing to be slapped down?" , "'Self-important, overweening (6)'" , "Snobbish" .)