set phrase vs phrasal idiom

set phrase and phrasal idiom both are nouns.

Word	Noun	Adjective	Verb	Adverb
set phrase	Yes	No	No	No
phrasal idiom	Yes	No	No	No

As nouns, set phrase and phrasal idiom are synonyms defined as:

set phrase and phrasal idiom: an expression whose meanings cannot be inferred from the meanings of the words that make it up

Other synonyms of set phrase include idiom, idiomatic expression, phrase.

set phrase (noun)	phrasal idiom (noun)
an expression whose meanings cannot be inferred from the meanings of the words that make it up	an expression whose meanings cannot be inferred from the meanings of the words that make it up