lanthanon vs rare earth

lanthanon and rare earth both are nouns.

Word	Noun	Adjective	Verb	Adverb
lanthanon	Yes	No	No	No
rare earth	Yes	No	No	No

As nouns, lanthanon and rare earth are synonyms defined as:

lanthanon and rare earth: any element of the lanthanide series (atomic numbers 57 through 71)

Other synonyms of lanthanon include lanthanide, lanthanoid, rare-earth element.

lanthanon (noun)	rare earth (noun)
any element of the lanthanide series (atomic numbers 57 through 71)	any element of the lanthanide series (atomic numbers 57 through 71)