lamp vs limelight

lamp and limelight both are nouns.

Word	Noun	Adjective	Verb	Adverb
lamp	Yes	No	No	No
limelight	Yes	No	No	No

As nouns, limelight is a hyponym of lamp; that is, limelight is a word with a more specific, narrower meaning than lamp:

lamp: an artificial source of visible illumination
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

lamp (noun)	limelight (noun)
an artificial source of visible illumination	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 piece of furniture holding one or more electric light bulbs	a focus of public attention