psychotherapy group vs meeting

psychotherapy group and meeting both are nouns.

Word	Noun	Adjective	Verb	Adverb
psychotherapy group	Yes	No	No	No
meeting	Yes	No	No	No

As nouns, meeting is a hypernym of psychotherapy group; that is, meeting is a word with a broader meaning than psychotherapy group:

Other hypernyms of psychotherapy group include group meeting.

psychotherapy group (noun)	meeting (noun)
a meeting of people for psychotherapeutic purposes	the social act of assembling for some common purpose
	the act of joining together as one
	a casual or unexpected convergence
	a formally arranged gathering
	a small informal social gathering
	a place where things merge or flow together (especially rivers)