halo vs fairy circle

halo and fairy circle both are nouns.

Word	Noun	Adjective	Verb	Adverb
halo	Yes	No	No	No
fairy circle	Yes	No	No	No

As nouns, fairy circle is a hyponym of halo; that is, fairy circle is a word with a more specific, narrower meaning than halo:

halo: a toroidal shape
fairy circle: a ring of fungi marking the periphery of the perennial underground growth of the mycelium

Other hyponyms of halo include fairy ring.

halo (noun)	fairy circle (noun)
an indication of radiant light drawn around the head of a saint	a ring of fungi marking the periphery of the perennial underground growth of the mycelium
a circle of light around the sun or moon
a toroidal shape