n. | 1. | |
| 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 |
| 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. |