In finance: A certificate representing a share of ownership in a company. Stock is the ownership of a corporation represented by shares that are a claim on the corporation's earnings and assets. There are many kinds of stocks, the most widely known being common stock, which usually entitles a stockholder to vote in the election of directors and other corporate matters.
In viticulture: Grape variety used as the underground portion of a grafted vine onto which the scion is grafted. Bred to provide pest resistance and/or adaptability to unfavorable soil or environmental conditions. Also known as a rootstock.