terrorist act vs 9/11

terrorist act and 9/11 both are nouns.

Word	Noun	Adjective	Verb	Adverb
terrorist act	Yes	No	No	No
9/11	Yes	No	No	No

terrorist act (noun)	9/11 (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	the day in 2001 when Arab suicide bombers hijacked United States airliners and used them as bombs