spe‧cial‧ty plural specialities [countable] American English
a type of food that a person, restaurant, or area is well known for [= speciality British English]
Our specialty is clam chowder.
a subject or job that you know a lot about or have a lot of experience of [= speciality British English]
Johnson's specialty is medieval European history.
a particular product or business that has one purpose or sells one type of thing:
an area with clothes retailers and specialty shops