import vs subject matter

import and subject matter both are nouns.

Word	Noun	Adjective	Verb	Adverb
import	Yes	No	Yes	No
subject matter	Yes	No	No	No

As nouns, subject matter is a hypernym of import; that is, subject matter is a word with a broader meaning than import:

Other hypernyms of import include content, message, substance.

import (noun)	subject matter (noun)
commodities (goods or services) bought from a foreign country	content communicating a message; what something is about
having important effects or influence
a meaning that is not expressly stated but can be inferred
the message that is intended or expressed or signified
an imported person brought from a foreign country

import (verb)	subject matter (verb)
indicate or signify
bring in from abroad
transfer (electronic data) into a database or document