Proud, contrary attempt to break rank (8)
I believe the answer is:
arrogant
'proud' is the definition.
(similar in meaning)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for arrogant that I've seen before include "Conceited, self-important" , "Proud and overbearing, feeling superior" , "Over-cocky" , "Overweening" , "Overbearingly proud" .)