pilot light vs indicator lamp

pilot light and indicator lamp both are nouns.

Word	Noun	Adjective	Verb	Adverb
pilot light	Yes	No	No	No
indicator lamp	Yes	No	No	No

As nouns, pilot light and indicator lamp are synonyms defined as:

pilot light and indicator lamp: indicator consisting of a light to indicate whether power is on or a motor is in operation

Other synonyms of pilot light include pilot lamp.

pilot light (noun)	indicator lamp (noun)
indicator consisting of a light to indicate whether power is on or a motor is in operation	indicator consisting of a light to indicate whether power is on or a motor is in operation
small auxiliary gas burner that provides a flame to ignite a larger gas burner