source

Etymology

From Middle English sours, from Old French sorse (“rise, beginning, spring, source”), from sors, past participle of sordre, sourdre, from Latin surgō (“to rise”), which is composed of sub- (“up from below”) + regō (“lead, rule”), ultimately from Proto-Indo-European *h₃réǵeti (“to straighten; right”), from the root *h₃reǵ-. See surge.

noun

1. The person, place, or thing from which something (information, goods, etc.) comes or is acquired.
   The accused refused to reveal the source of the illegal drugs she was selling.
   More than a mere source of Promethean sustenance to thwart the cold and cook one's meat, wood was quite simply mankind's first industrial and manufacturing fuel. 2006, Edwin Black, chapter 2, in Internal Combustion
   Investors face a quandary. Cash offers a return of virtually zero in many developed countries; government-bond yields may have risen in recent weeks but they are still unattractive. Equities have suffered two big bear markets since 2000 and are wobbling again. It is hardly surprising that pension funds, insurers and endowments are searching for new sources of return. 2013-07-06, “The rise of smart beta”, in The Economist, volume 408, number 8843, page 68
2. 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.
   Most of the Himalayan rivers have been relatively untouched by dams near their sources. Now the two great Asian powers, India and China, are rushing to harness them as they cut through some of the world's deepest valleys. 2013-08-16, John Vidal, “Dams endanger ecology of Himalayas”, in The Guardian Weekly, volume 189, number 10, page 8
3. A reporter's informant.
4. (computing) Source code.
5. (electronics) The name of one terminal of a field effect transistor (FET).
6. (graph theory) A node in a directed graph whose edges all go out from it; one with no entering edges.

verb

1. To obtain or procure: used especially of a business resource.
   But the point when it would have to look at alternative new-build vehicles was always looming large, and there would inevitably be a finite number of Class 66s it could source from elsewhere, and a limit to other locomotives it could re-power. July 12 2023, Pip Dunn, “Class 99s: "ultimate Electro-Diesel"”, in RAIL, number 987, page 52
2. (transitive) To find information about (a quotation)'s source (from which it comes): to find a citation for.