INDICATOR • DICTIONARY ONE.COM • Definition of Indicator

Add this Dictionary
to your website!
See more options...

/ˈɪndəkˌeɪtər/ Listen

noun

Indicator n.

1.

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

2.

(Mach.) 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; as:

(a)

(Steam Engine) 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).

(b)

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

3.

(Mech.) The part of an instrument by which an effect is indicated, as an index or pointer.

4.

(Zool.) Any bird of the genus Indicator and allied genera. See Honey guide, under Honey.

5.

(Chem.) 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. Note: The common indicators are litmus, tropaeolin, phenol phthalein, potassic permanganate, etc.

Indicator card, the figure drawn by an engine indicator, by means of which the working of the engine can be investigated and its power calculated. The Illustration shows one form of indicator card, from a steam engine, together with scales by which the pressure of the steam above or below that of the atmosphere, corresponding to any position of the engine piston in its stroke, can be measured. Called also indicator diagram.

Indicator telegraph, a telegraph in which the signals are the deflections of a magnetic needle, as in the trans-Atlantic system.

See images of 'Indicator'

Etymology of 'Indicator'

Collaborative International Dictionary of English 0.48

Share |

Add this dictionary
to your browser search bar

"Indicator" Quotes from Famous Books

... of 1,300 pounds was sanctioned by the Local Government Board for defraying the cost of the extension of the Reference Library and fittings, the purchase of a Cotgreave Indicator, installed in 1897, the restoration of the exterior stonework of the building, and interior decoration and repairs. The total expenditure amounted to 1,740 pounds, the difference between the cost and the amount of the loan ...

— Three Centuries of a City Library • George A. Stephen

... the two sides of the water to the inevitable result of opening it to home-circulation—the necessity of knowing whether a given book is or is not on the shelves. The American response was to open the shelves, the British, to create an additional piece of machinery—the indicator. These two results might have been predicted in advance by one familiar with the temper of the two peoples. It has shown itself in scores of instances, in the front yards of residences, for instance—walled off in England and open to the ...

— A Librarian's Open Shelf • Arthur E. Bostwick

... the white locks of Thorwaldsen was such an one,—the eye of immortal youth, the indicator of the man's whole aspect in a future sphere. We have scanned such eyes closely; when near, we saw that the lids were red, the corners defaced with ominous marks, the orb looked faded and tear-stained; but when we retreated ...

— Woman in the Ninteenth Century - and Kindred Papers Relating to the Sphere, Condition - and Duties, of Woman. • Margaret Fuller Ossoli

... Passero has several messengers who travel to and fro in secret. Mademoiselle Lisette was once one of them. She has travelled many times the length and breadth of Europe. But nowadays she is an indicator—and a very clever one indeed," he added ...

— Mademoiselle of Monte Carlo • William Le Queux

... illuminated shops on either side. On his right stood a weighing machine and an automatic figure. Without a moment's hesitation he jumped on the little platform of the weighing machine and slipped a penny in the slot. As he was quite sure that he weighed eleven stone, he could not help smiling when the indicator registered only one. Either the machine has gone wrong, he thought, or I have been transported to some other planet, ten times larger, or ten times smaller than the earth; he had been a pupil at the School of Navigation, you see, and knew ...

— In Midsummer Days and Other Tales • August Strindberg

Copyright © 2025 Dictionary One.com