calcium light vs limelight

calcium light and limelight both are nouns.

Word	Noun	Adjective	Verb	Adverb
calcium light	Yes	No	No	No
limelight	Yes	No	No	No

As nouns, calcium light and limelight are synonyms defined as:

calcium light and limelight: a lamp consisting of a flame directed at a cylinder of lime with a lens to concentrate the light; formerly used for stage lighting

calcium light (noun)	limelight (noun)
a lamp consisting of a flame directed at a cylinder of lime with a lens to concentrate the light; formerly used for stage lighting	a lamp consisting of a flame directed at a cylinder of lime with a lens to concentrate the light; formerly used for stage lighting
	a focus of public attention