Beaver and Opera hat

Beaver noun - A man's hat with a tall crown; usually covered with silk or with beaver fur.

Opera hat is a synonym for beaver. In some cases you can use "Opera hat" instead a noun "Beaver". popular alternative

Opera hat noun - A man's hat with a tall crown; usually covered with silk or with beaver fur.

Beaver is a synonym for opera hat. You can use "Beaver" instead a noun phrase "Opera hat".