What Exactly IS a Tea Gown?

Pretty new teacup from Sacramento.

There is a tea coming up, to which my Lady Mother and I have been invited, and we're quibbling over what to wear.  In our modern-American-brains we both thought "tea gowns, of course," garments neither of us possess.  So I went off looking for references, just out of curiosity, and got a bit of an education on what a tea gown actually is.

I had thought a tea gown was a frothy-ish dress worn indoors, late in the day (teatime, of course).  What I learned is that tea gowns were actually a garment worn as "undress," in one's own home only, in order to receive visitors.  They were never worn *out* of the home, never worn for visiting, and were typically worn without corsets.  Tea gowns were literally really fancy, slightly fitted bathrobes.

Here is a selection of late Victorian tea gowns I collected from The Met online collections:

1891 - not my favorite design, but I like the tie around the waist, and the loose fit.

1875.  Beautiful, frothy, and not worn with a corset, but with a snug-fitting bodice.

1880.  Gorgeous.

1880 - the back.  Love the train, and the jacket-like fit to the back.

1885 - my absolute favorite.  It has a Chemise a la Reine feel to it. 

1890 - beautiful color and a lovely train out the back.  It almost looks 1870s, yeah?

 My conclusion is that I will need to wear a visiting dress (a day dress) to this tea up in Virginia City, not a tea gown.  Do I have a Victorian day dress?  Yes, yes I do...tea hee!