Indicator ¹

Definition: One who, or that which, shows or points out; as, a fare indicator in a street car.

Indicator ²

Definition: 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

Indicator ³

Definition: 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).

Indicator ⁴

Definition: A telltale connected with a hoisting machine, to show, at the surface, the position of the cage in the shaft of a mine, etc.

Indicator ⁵

Definition: The part of an instrument by which an effect is indicated, as an index or pointer.

Indicator ⁶

Definition: Any bird of the genus Indicator and allied genera. See Honey guide, under Honey.

Indicator ⁷

Definition: 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.

indicator ⁸

Definition: a device for showing the operating condition of some system

indicator ⁹

Definition: a number or ratio (a value on a scale of measurement) derived from a series of observed facts; can reveal relative changes as a function of time

indicator ¹⁰

Definition: a signal for attracting attention

indicator ¹¹

Definition: (chemistry) a substance that changes color to indicate the presence of some ion or substance; can be used to indicate the completion of a chemical reaction or (in medicine) to test for a particular reaction