long suit vs metier

long suit and metier both are nouns.

Word	Noun	Adjective	Verb	Adverb
long suit	Yes	No	No	No
metier	Yes	No	No	No

As nouns, long suit and metier are synonyms defined as:

Other synonyms of long suit include forte, speciality, specialty, strength, strong point, strong suit.

long suit (noun)	metier (noun)
an asset of special worth or utility	an occupation for which you are especially well suited
in a hand, the suit having the most cards	an asset of special worth or utility