stalk: (noun) the stem of a plant; a similar supporting structure on other objects; (verb) to pursue persistently, often with the intention to harass or harm
stock: (noun) goods or inventory kept available for sale or use; (finance) shares of a company; (culinary) the base of a soup, sauce, or stew; (verb) to keep a supply of items to have on hand or make available for sale (e.g. to stock shelves in a store)