You out and out Caper you!
I bet you thought Strathspey was only a dance!
Before it was that, it was (and is) a place i.e. the Strath (wide valley) of the River Spey. It was the way that they did a particular dance in Spey region that the dance took its name.
This information is useful also for those who think Glengarry or Balmoral are merely names of men's bonnets.