Resentful canine perhaps time will break (6)
I believe the answer is:
bitter
'resentful' is the definition.
(synonyms)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for bitter that I've seen before include "Tart like some English beer" , "Act nervously" , "Acrimonious; beer" , "Kind of British beer" , "Sour kind of English ale?" .)