test ban vs banning

test ban and banning both are nouns.

Word	Noun	Adjective	Verb	Adverb
test ban	Yes	No	No	No
banning	Yes	No	No	No

As nouns, banning is a hypernym of test ban; that is, banning is a word with a broader meaning than test ban:

test ban: a ban on the testing of nuclear weapons that is mutually agreed to by countries that possess nuclear weapons
banning: an official prohibition or edict against something

Other hypernyms of test ban include ban, forbiddance, forbidding.

test ban (noun)	banning (noun)
a ban on the testing of nuclear weapons that is mutually agreed to by countries that possess nuclear weapons	an official prohibition or edict against something