pilot lamp vs pilot light

pilot lamp and pilot light both are nouns.

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

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

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

Other synonyms of pilot lamp include indicator lamp.

pilot lamp (noun)	pilot light (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