sanctum vs sanctum sanctorum

sanctum and sanctum sanctorum both are nouns.

Word	Noun	Adjective	Verb	Adverb
sanctum	Yes	No	No	No
sanctum sanctorum	Yes	No	No	No

As nouns, sanctum and sanctum sanctorum are synonyms defined as:

sanctum (noun)	sanctum sanctorum (noun)
a place of inviolable privacy	(Judaism) sanctuary comprised of the innermost chamber of the Tabernacle in the temple of Solomon where the Ark of the Covenant was kept
a sacred place of pilgrimage	a place of inviolable privacy