It's 'waist' when referring to your belt or belly button line

I'm on a pretty good income, my partner and I can afford a one month overseas holiday every year or so and I dress in a mix of jeans off the internet, chosen for their lifespan, and hawaiian shirts from a mass market fashion store

I dress brightly, not at all expensively. When I dressed a lot like this as a kid in the '80s I had to change before the family went to a club for dinner in order to meet the dress code. The clubs are more relaxed now.

You really can't judge people's wealth on their dress standards, though there is class encoded in clothes