specialty

(noun) an asset of special worth or utility. Synonyms: forte, strong suit, long suit, metier, speciality, strong point, strength. Example: "Cooking is his forte."

(noun) a distinguishing trait. Synonyms: peculiarity, specialness, speciality, distinctiveness.

(noun) the special line of work you have adopted as your career. Synonyms: specialization, specialisation, speciality, specialism. Example: "His specialization is gastroenterology."