From Knitting Lingerie Style:
I call this design the One-Piece Wonder because it serves the purpose of four undergarments: It smooths the torso like a slip, uplifts and enhances the bust like an under wire bra, holds up stockings like a garter belt, and gives the coverage of a panty. I’ve based it on it’s 1920s forebear the cami-knicker, a lingerie piece that combined a camisole with short pants that fastened at the crotch.
Traditionally, commercial body-shaping garments, such as girdles and longline bras have been fairly basic in design, but I’ve dressed this one up with a silk yarn combined with elasticized cotton and a tulle ruffle at the bust. The combination gives just the right amount of vintage appeal along with sleek modern functionality. Partnered with a dressy skirt and cardigan, you’ll have a perfect lingerie-inspired evening look, or wear it completely undercover for a functional piece of underpinning.