toilet paper vs tissue

toilet paper and tissue both are nouns.

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

As nouns, tissue is a hypernym of toilet paper; that is, tissue is a word with a broader meaning than toilet paper:

Other hypernyms of toilet paper include tissue paper.

toilet paper (noun)	tissue (noun)
a soft thin absorbent paper for use in toilets	part of an organism consisting of an aggregate of cells having a similar structure and function
	a soft thin (usually translucent) paper

toilet paper (verb)	tissue (verb)
	create a piece of cloth by interlacing strands of fabric, such as wool or cotton