a. a spring that forms the starting point of a stream; headspring
b. the area where the headwaters of a river rise
2. anything, such as a story or work of art, that provides a model or inspiration for a later work
3. Electronics the electrode region in a field-effect transistor from which majority carriers flow into the interelectrode conductivity channel
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.
the point of origin of a river.
The source, which may be a lake outlet or a stream receiving its water from a spring, swamp, or glacier, ordinarily corresponds to the place where the permanent channel of the watercourse appears. In a river system having multiple sources, the main source is considered the one farthest from the mouth and largest in volume. It is not unusual for the main channel of a river and its sources to have different names; for instance, the Severnaia Dvina is formed by the confluence of the Sukhona and the lug, the Amur by that of the Shilka and Argun’.
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
The circuit or device that supplies signal power or electric energy or charge to a transducer or load circuit.
The terminal in a field-effect transistor from which majority carriers flow into the conducting channel in the semiconductor material.
The vertex with indegree 0 that is specified in the definition of an s-t network.
A radioactive material packaged so as to produce radiation for experimental or industrial use.
In general, a device that supplies some extensive entity, such as energy, matter, particles, or electric charge.
A point, line, or area at which mass or energy is added to a system, either instantaneously or continuously.
A point at which lines of force in a vector field originate, such as a point in an electrostatic field where there is positive charge.
The arc or spark that supplies light for a spectroscope.
A device that supplies heat.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.