Piltdown hoax vs Piltdown man

Piltdown hoax and Piltdown man both are nouns.

Word	Noun	Adjective	Verb	Adverb
Piltdown hoax	Yes	No	No	No
Piltdown man	Yes	No	No	No

As nouns, Piltdown hoax and Piltdown man are synonyms defined as:

Piltdown hoax and Piltdown man: a supposedly primitive man later proven to be a hoax

Piltdown hoax (noun)	Piltdown man (noun)
a supposedly primitive man later proven to be a hoax	a supposedly primitive man later proven to be a hoax