Wikipedia
A bathing dress was a mode of dress used for ladies' swimming/bathing activities during the 19th Century. These bathing costumes originally included ankle length dresses, long pants, and long sleeves. Around the 1880s the sleeves and hemlines of these dresses were shortened to improve range of motion and general comfort.
Usage examples of "bathing dress".
Bloodstains dropped on the pavement from the bathing dress hanging above, and being a red bathing dress, of course, the criminals themselves did not realize it was bloodstained.
He took in the well-controlled figure in its skirted bathing dress, he noticed the gold cross hanging between the crepey breasts, and he shuddered and vowed he would never let Helen get like that.
There's no swimming-pool where a girl could sit around in a pretty bathing dress, although it can be hot there, oh my word.
I won't say I knew just what they were doing in there, but I did think of my sister holding up her bathing dress for the Sugi boy.
One of the thugs climbed out first, followed by the girl, the white bottom of her bathing dress lascivious below Bond's coat, then Bond, then the second thug.