rusticism vs phrasal idiom

rusticism and phrasal idiom both are nouns.

Word	Noun	Adjective	Verb	Adverb
rusticism	Yes	No	No	No
phrasal idiom	Yes	No	No	No

As nouns, phrasal idiom is a hypernym of rusticism; that is, phrasal idiom is a word with a broader meaning than rusticism:

rusticism: a rural idiom or expression
phrasal idiom: an expression whose meanings cannot be inferred from the meanings of the words that make it up

Other hypernyms of rusticism include idiom, idiomatic expression, phrase, set phrase.

rusticism (noun)	phrasal idiom (noun)
a rural idiom or expression	an expression whose meanings cannot be inferred from the meanings of the words that make it up