pilot lamp

noun

1. an electric lamp, used in association with a control, which by means of position or color indicates the functioning of the control; an indicator light or a control light.

pilot lamp

noun

1. a small light in an electric circuit or device that lights up when the circuit is closed or when certain conditions prevail

Word History and Origins

Origin of pilot lamp¹

First recorded in 1880–85

Example Sentences

The details of the operator's cord circuit and of the pilot lamp and night alarm circuits will be clear from the diagram.

From Project Gutenberg

This controls, as already described, the circuit of the pilot lamp common to the same group of line lamps.

From Project Gutenberg