Supply is defined as: The specific quantities of a good or service consumers are willing and able to buy at alternate prices in a given time period, ceteris paribus. The ability and willingness to buy specific quantities of a good at alternate prices in a given time period, ceteris paribus. The specific quantities of a good or service producers are willing and able to supply at alternate prices in a given time period, ceteris paribus. The specific quantities of a good or service consumers are willing and able to supply at alternate prices in a given time period, ceteris paribus.