oesophagus vs British spelling

oesophagus and British spelling both are nouns.

Word	Noun	Adjective	Verb	Adverb
oesophagus	Yes	No	No	No
British spelling	Yes	No	No	No

oesophagus (noun)	British spelling (noun)
the passage between the pharynx and the stomach	English orthography used in the UK, Ireland and most of the Commonwealth (characterized by 'analyse', 'centre' and 'useable')