What grammatical name is given to the phrase " whose members share similar attitudes"

Noun phrase

correct.

I believe the phrase functions as an adjective, not a noun.

yes

www.chompchomp.com/terms/relativeclause.htm

The grammatical name given to the phrase "whose members share similar attitudes" is a relative clause. Specifically, it is a possessive relative clause, as it uses the possessive form "whose" to indicate possession or association.

To determine the grammatical name of a phrase like this, you can break it down into its components. In this case, the key elements are the pronoun "whose" and the noun phrase "members share similar attitudes." The pronoun "whose" acts as a possessive determiner, linking to the noun "members." The noun phrase "members share similar attitudes" functions as the subject of the relative clause.

By understanding the structure and function of the different parts of the phrase, you can identify the grammatical term for it, which is a relative clause.