British East Africa vs district

British East Africa and district both are nouns.

Word	Noun	Adjective	Verb	Adverb
British East Africa	Yes	No	No	No
district	Yes	No	Yes	No

As nouns, district is a hypernym of British East Africa; that is, district is a word with a broader meaning than British East Africa:

British East Africa: the former British territories of eastern Africa, including Kenya, Tanganyika, Uganda, and Zanzibar
district: a region marked off for administrative or other purposes

Other hypernyms of British East Africa include dominion, territorial dominion, territory.

British East Africa (noun)	district (noun)
the former British territories of eastern Africa, including Kenya, Tanganyika, Uganda, and Zanzibar	a region marked off for administrative or other purposes

British East Africa (verb)	district (verb)
	regulate housing in; of certain areas of towns