noun

1. A sudden thought, particularly one that solves a long-standing problem.

   “I had been working on the problem for weeks, and then I had a brainstorm and saw that the solution was easy.”

2. A session of brainstorming, investigating a problem to try to find solutions.

3. An unexpected mental error.

Synonyms: brainwave

verb

1. To investigate something, or solve a problem using brainstorming.

2. To participate in a brainstorming session.