WordNet sense 1 (an asset of special worth or utility):

metier, speciality, specialty, strength, long suit, strong suit, strong point

WordNet sense 2 (chiefly a direction or description in music):

fortissimo

WordNet sense 3 (used chiefly as a direction or description in music):

loud

WordNet sense 4 (used as a direction in music; to be played relatively loudly):

loudly