act of terrorism vs Black September

act of terrorism and Black September both are nouns.

Word	Noun	Adjective	Verb	Adverb
act of terrorism	Yes	No	No	No
Black September	Yes	No	No	No

act of terrorism (noun)	Black September (noun)
the calculated use of violence (or the threat of violence) against civilians in order to attain goals that are political or religious or ideological in nature; this is done through intimidation or coercion or instilling fear	a Palestinian international terrorist organization that split from the PLO in 1974; has conducted terrorist attacks in 20 countries