maths vs monotone

maths and monotone both are nouns.

Word	Noun	Adjective	Verb	Adverb
maths	Yes	No	No	No
monotone	Yes	Yes	No	No

maths (noun)	monotone (noun)
a science (or group of related sciences) dealing with the logic of quantity and shape and arrangement	an unchanging intonation
	a single tone repeated with different words or different rhythms (especially in rendering liturgical texts)

maths (adjective)	monotone (adjective)
	of a sequence or function; consistently increasing and never decreasing or consistently decreasing and never increasing in value
	sounded or spoken in a tone unvarying in pitch