I've heard people use the term plant-based instead of vegan.
Vegans don't use or eat animal products, which like you say include eschewing leather, fur, feathers, silk, as well as the more obvious things like meat, honey, fish, dairy and eggs.
Plenty of people aren't vegan but would describe themselves as plant-based, in that they largely avoid animal products, but not strictly. Someone plant-based might get a vegan burger but not be that bothered checking their new belt isn't leather. They might usually avoid dairy, but on holiday they really fancy an ice cream and do it.
The definition of vegan is very clear, but the increasing numbers of people who are plant-based can end up muddying the waters a bit for people who aren't sure what veganism is. I know I've been places before where they've said something is vegan, the ingredients turn out to have honey in, and they've been shocked because apparently they've had vegans before with no issues with honey so they assumed honey was fine. Those people aren't vegan, regardless of calling themselves vegan. If you consume or use animal products you're not vegan. It's a bit like calling yourself vegetarian and eating fish, you can give yourself any name you like, nobody can stop you. Doesn't make it accurate.