Cumulative Preferred Stock

What Does Cumulative Preferred Stock Mean?
A type of preferred stock with a provision that stipulates that if any dividends have been omitted in the past, they must be paid out to preferred shareholders first, before common shareholders can receive dividends.  

Investopedia explains Cumulative Preferred Stock
A preferred stock will typically have a fixed dividend yield based on the par value of the stock. This dividend is paid out at set intervals, usually quarterly, to preferred holders. If a company runs into some financial problems and is unable to meet all of its obligations, it will likely suspend its dividend payments and focus on paying the business-specific expenses. If the company gets through the trouble and starts paying out dividends again, it will first have to pay back all of the dividends that are owed to preferred share holders.