terrorist group vs IRA

terrorist group and IRA both are nouns.

Word	Noun	Adjective	Verb	Adverb
terrorist group	Yes	No	No	No
IRA	Yes	No	No	No

terrorist group (noun)	IRA (noun)
a political movement that uses terror as a weapon to achieve its goals	a retirement plan that allows you to contribute a limited yearly sum toward your retirement; taxes on the interest earned in the account are deferred
	a militant organization of Irish nationalists who used terrorism and guerilla warfare in an effort to drive British forces from Northern Ireland and achieve a united independent Ireland