Can I stain without stripping?
You can use "furniture glaze" (pretty much a tinted "clear" finish.)

You could tint/dye a clear finish, or use a naturally tinted "clear" finish such as dark shellac.

For both of those you'd likely need to at least scuff-sand the current finish to get good adhesion.

You can also use a colored/tinted furniture wax over the current finish.