A type of security that signifies ownership in a corporation and represents a claim on part of the corporation's assets and earnings.
There are two main types of stock: common and preferred. Common stock usually entitles the owner to vote at shareholders' meetings and to receive dividends. Preferred stock generally does not have voting rights, but has a higher claim on assets and earnings than the common shares. For example, owners of preferred stock receive dividends before common shareholders and have priority in the event that a company goes bankrupt and is liquidated.
Convertibles
Securities, usually bonds or preferred shares, that can be converted into common stock.
The definition you provided has nothing to do with a "price reset" by the company for any purpose. It refers to the contract price of stock or convertibles being offered in conjunction with PIPE financing.