1. To beat, flail, or strike someone or something violently or wildly. The wind lashed at our windows so hard that I thought they might actually break at one point. The warden lashed at the prisoners with a whip for failing to move quickly enough.

2. To criticize, rebuke, or react to someone or something with sudden, intense anger. Often worded as "lash out at (someone or something)." The boss lashed at the intern for mixing up the documents for the year-end audit. The senator lashed out at reporters for continuing to question his role in the controversy.