vitreous humour vs vitreous humor

vitreous humour and vitreous humor both are nouns.

Word	Noun	Adjective	Verb	Adverb
vitreous humour	Yes	No	No	No
vitreous humor	Yes	No	No	No

As nouns, vitreous humour and vitreous humor are synonyms defined as:

vitreous humour and vitreous humor: the clear colorless transparent jelly that fills the posterior chamber of the eyeball

Other synonyms of vitreous humour include vitreous body.

vitreous humour (noun)	vitreous humor (noun)
the clear colorless transparent jelly that fills the posterior chamber of the eyeball	the clear colorless transparent jelly that fills the posterior chamber of the eyeball