to react with irritation, anger or fear; display temper or indignation (“bristling” is the noun)
I recall a scene the morning after my first fight with Jack Dempsey as one of the strangest I ever experienced. It had me disconcerted, as well as considerably embarrassed. After that bout in the rain in Philadelphia it seemed to me proper to go and pay my respects to Jack. He had been severely punished, and must feel pretty blue after losing the championship. The next afternoon I went to his hotel. He had a suite of rooms, and when I got there Jack was in an inside bedroom. In the outer room were gathered the Dempsey entourage of manager, handlers, trainers, and disappointed followers. They greeted me with an instant bristling of hostility. I was the focus of scowls and angry, sullen glances. Gene Normile was in tears. Jerry the Greek came to me, shook his fist, and mumbled hoarsely, “You can’t licka the ‘Chump,’ you can’t licka the ‘Chump.’” Jack Dempsey always inspired loyalty, and this was it. They bitterly resented my defeating him.
Gene Tunney June 1939