electric-discharge lamp vs gas-discharge lamp

electric-discharge lamp and gas-discharge lamp both are nouns.

Word	Noun	Adjective	Verb	Adverb
electric-discharge lamp	Yes	No	No	No
gas-discharge lamp	Yes	No	No	No

As nouns, electric-discharge lamp and gas-discharge lamp are synonyms defined as:

electric-discharge lamp and gas-discharge lamp: an electric lamp in which the light comes from an electric discharge between two electrodes in a glass tube

electric-discharge lamp (noun)	gas-discharge lamp (noun)
an electric lamp in which the light comes from an electric discharge between two electrodes in a glass tube	an electric lamp in which the light comes from an electric discharge between two electrodes in a glass tube