Possible meanings are 1) the Israelites traveled around the mountain called Seir for a very long time or 2) the Israelites wandered in a region called Mount Seir for a very long time.
This is a mountainous area south of the Dead Sea. The area is also called "Edom." See how you translated this in [Deuteronomy 1:2](../01/02.md) (See: [[rc://en/ta/man/translate/translate-names]])