terrorist organization vs terrorist group

terrorist organization and terrorist group both are nouns.

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

As nouns, terrorist organization and terrorist group are synonyms defined as:

terrorist organization and terrorist group: a political movement that uses terror as a weapon to achieve its goals

Other synonyms of terrorist organization include foreign terrorist organization, FTO.

terrorist organization (noun)	terrorist group (noun)
a political movement that uses terror as a weapon to achieve its goals	a political movement that uses terror as a weapon to achieve its goals