- (n.) Any bird of the genus Indicator and allied genera. See Honey guide, under Honey.
- (n.) A pressure gauge; a water gauge, as for a steam boiler; an apparatus or instrument for showing the working of a machine or moving part.
- (n.) The part of an instrument by which an effect is indicated, as an index or pointer.
- (n.) A telltale connected with a hoisting machine, to show, at the surface, the position of the cage in the shaft of a mine, etc.
- (n.) An instrument which draws a diagram showing the varying pressure in the cylinder of an engine or pump at every point of the stroke. It consists of a small cylinder communicating with the engine cylinder and fitted with a piston which the varying pressure drives upward more or less against the resistance of a spring. A lever imparts motion to a pencil which traces the diagram on a card wrapped around a vertical drum which is turned back and forth by a string connected with the piston rod of the engine. See Indicator card (below).
- (n.) One who or that which, shows or points out; as, a fare indicator in a street car.
- (n.) That which indicates the condition of acidity, alkalinity or the deficiency, excess or sufficiency of a standard reagent, by causing an appearance, disappearance or change of color, as in titration or volumetric analysis.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). indicator. Retrieved September 20, 2026, from http://smartdefine.org/indicator/definitions/2020812 |
| Chicago | Webster's. 2011. "indicator" http://smartdefine.org/indicator/definitions/2020812 (accessed September 20, 2026). |
| Harvard | Webster's 2011, indicator, Smart Define, viewed 20 September, 2026, <http://smartdefine.org/indicator/definitions/2020812>. |
| MLA | Webster's. "indicator" 27 May 2011. Web. 20 September 2026. <http://smartdefine.org/indicator/definitions/2020812> |