box sill
noun Carpentry.
a sill for a building frame, composed of a plate resting on the basement wall and a joist or header at the outer edge of the plate, as well as a soleplate for the studs resting either directly on the joists or on the rough flooring.
Compare
L sill.
Words nearby box sill
box plot,
box room,
box score,
box seat,
box set,
box sill,
box social,
box spanner,
box spring,
box stall,
box staple