1. To attack or thrash something in an brutal, forceful, or relentless manner. He stood there whaling on the wall with a sledgehammer, but he barely seemed to be making a dent in it. She began whaling on the poor child until a police officer finally intervened. The other team whaled on us for the entire game, leading to one of our most humiliating defeats of the season.

2. To criticize, rebuke, or verbally assault someone or something vehemently or relentlessly. The interviewer suddenly began whaling on the politician over his alleged ties to the pharmaceutical industry. The boss whaled on us for the entirety of the meeting because of our failure to meet our sales quota.