toilet paper vs bathroom tissue

toilet paper and bathroom tissue both are nouns.

Word	Noun	Adjective	Verb	Adverb
toilet paper	Yes	No	No	No
bathroom tissue	Yes	No	No	No

As nouns, toilet paper and bathroom tissue are synonyms defined as:

toilet paper and bathroom tissue: a soft thin absorbent paper for use in toilets

Other synonyms of toilet paper include toilet tissue.

toilet paper (noun)	bathroom tissue (noun)
a soft thin absorbent paper for use in toilets	a soft thin absorbent paper for use in toilets