What is smart casual?

[Kayzr]

We are going on a diner train in July and have been told that the dress code is smart casual. But neither DH or myself are quite sure what that is. So could you help please?

We don't want to stick out like sore thumbs.

Thanks.

anything other than jeans/trainers type thing

I tend to think of it as the step below black tie- a suit/ tousers and a jacket for your DH and a frock/ trouser suit/ skirt and a top for you. Meeting the inlaws for the first time tidy IYKWIM. Hope this helps.