Clothing worn under the bustline, lifting or accentuating the breasts. The top edge of the outer garment should ideally rest just underneath the bust.
Some clothing styles that incorporate this feature are maid uniforms, waitress uniforms (particularly from the Anna Miller and Kobeya restaurant chains), the dirndl, most corsets, and the virgin killer outfit.
For clothing that encloses all sides of the bust, use framed breasts.
Not to be confused with underboob, which refers to the exposed bottom part of the breasts.