rib

Concise Oxford English Dictionary © 2008 Oxford University Press:
rib/rɪb/

▶noun

• 1 each of a series of slender curved bones articulated in pairs to the spine, protecting the thoracic cavity and its organs.

  ■ an animal rib with meat adhering to it used as food.

• 2 Architecture a curved member supporting a vault or defining its form.

• 3 a curved transverse strut in a ship, forming part of the framework of the hull.

• 4 each of the curved pieces of wood forming the body of a lute or violin.

• 5 each of the hinged rods supporting the fabric of an umbrella.

• 6 Aeronautics a structural member in an aerofoil.

• 7 a vein of a leaf or an insect's wing.

• 8 Knitting alternate plain and purl stitches producing a ridged, slightly elastic fabric.

▶verb (ribs, ribbing, ribbed)

• 1 mark with or form into ridges.

  ■ provide with ribs.

• 2 informal tease good-naturedly.

– derivatives
ribber noun,
ribless adjective.

– origin OE rib, ribb, of Gmc origin.