fill in vs British English

fill in is not a noun while British English is a noun.

Word	Noun	Adjective	Verb	Adverb
fill in	No	No	Yes	No
British English	Yes	No	No	No

fill in (noun)	British English (noun)
	English as spoken in the UK

fill in (verb)	British English (verb)
supply with information on a specific topic
write all the required information onto a form
represent the effect of shade or shadow on
be a substitute