The combination of the words "spouse" and "bestie". A spouse who is also your best friend. A best friend who is also your spouse. Your partner for life and in crime. This term is gender neutral and can be used with non-binary and gender non-conforming folks.
I can't wait to see my spoustie tonight. They bring me such life and I am so happy to have someone like them in my life.
I love having a spoustie. It's the best of both worlds.