Used or employed for constant service or application, as if constituting a portion of a stock or supply; standard; permanent; standing; as, a stock actor; a stock play; a stock sermon.(adjective)
source: webster1913
noun (n)
the capital raised by a corporation through the issue of shares entitling holders to an ownership interest (equity)(noun.possession)
Example: He owns a controlling share of the company's stock.
source: wordnet30
the merchandise that a shop has on hand(noun.artifact)