source UK /sɔːs/US /sɔɹs/noun 7verb 2forms 3 noun7 •a person, a place or a thing that something comes from, such as information or moneyThe accused refused to reveal the source of the illegal drugs she was selling. •Spring; fountainhead; wellhead; any collection of water on or under the surface of the ground in which a stream originates.The main sources of the Euphrates River are the Karasu and Murat Rivers. •A reporter's informant. •Source code. •The name of one terminal of a field effect transistor (FET). •A node in a directed graph whose edges all go out from it; one with no entering edges. •The domain of a function; the object which a morphism points from. verb2 •To obtain or procure: used especially of a business resource. •To find information about (a quotation)'s source (from which it comes): to find a citation for. formssourced · sourcing · sources