Characterized by bitterness or resentment.
‘sixteen miserable months of rancorous disputes’
‘a rancorous debate’
‘He would often describe his wartime experiences in caustic, funny terms that would turn bitter and rancorous.’
‘There were rancorous battles over pronunciation.’
‘It seems to be aiming for a modern Catcher in the Rye with its sardonic, rancorous, troubled kid character.’
‘The rest of the piece was less rancorous, and I suggest you read the whole thing, to understand what I was trying to say.’