8k Definition

other
The form used by companies to comply with Securities and Exchange Commission requirements to report material developments. Although much case law has been developed to determine exactly what is a material development, the term means, in general, something that a reasonable shareholder would likely consider important to making an investment decision. Some material events include a planned merger, an out-of-the-ordinary purchase, the sale of significant assets, the resignation of the chief executive officer, the firing of the company’s auditor, or a bankruptcy filing.
Webster's New World Finance