macula vs plague spot

macula and plague spot both are nouns.

Word	Noun	Adjective	Verb	Adverb
macula	Yes	No	No	No
plague spot	Yes	No	No	No

As nouns, plague spot is a hyponym of macula; that is, plague spot is a word with a more specific, narrower meaning than macula:

macula: a patch of skin that is discolored but not usually elevated; caused by various diseases
plague spot: a spot on the skin characteristic of the plague

Other hyponyms of macula include freckle, lentigo, liver spot.

macula (noun)	plague spot (noun)
a small yellowish central area of the retina that is rich in cones and that mediates clear detailed vision	a spot on the skin characteristic of the plague
a patch of skin that is discolored but not usually elevated; caused by various diseases
a cooler darker spot appearing periodically on the sun's photosphere; associated with a strong magnetic field