mashie niblick vs seven iron

mashie niblick and seven iron both are nouns.

Word	Noun	Adjective	Verb	Adverb
mashie niblick	Yes	No	No	No
seven iron	Yes	No	No	No

As nouns, mashie niblick and seven iron are synonyms defined as:

mashie niblick and seven iron: iron with a lofted face for hitting high shots to the green

mashie niblick (noun)	seven iron (noun)
iron with a lofted face for hitting high shots to the green	iron with a lofted face for hitting high shots to the green