rib

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun One of a series of long curved bones occurring in 12 pairs in humans and extending from the spine to or toward the sternum.
• noun A similar bone in most vertebrates.
• noun A part or piece similar to a rib and serving to shape or support.
• noun A cut of meat enclosing one or more rib bones.
• noun Nautical One of many curved members attached to a boat or ship's keel and extending upward and outward to form the framework of the hull.
• noun One of many transverse pieces that provide an airplane wing with shape and strength.
• noun Architecture A long, narrow, usually arched member projecting from the surface of a structure, especially such a member separating the webs of a vault.
• noun A raised ridge or wale in knitted material or in cloth.
• noun Botany The main vein or any of the prominent veins of a leaf or other plant organ.
• noun Slang A teasing remark or action; a joke.
• transitive verb To shape, support, or provide with a rib or ribs.
• transitive verb To make with ridges or raised markings.
• transitive verb Informal To tease or make fun of.

from The Century Dictionary.

• noun An instrument for cleaning flax.
• noun An abbreviation of Royal Institute of British Architects.
• To furnish with ribs; strengthen or support by ribs: as, to rib a ship.
• To form into ribs or ridges; mark with alternate channels and projecting lines; ridge: as, to rib a field by plowing; to rib cloth.
• To inclose as with ribs; shut in; confine.
• noun Hound's-tongue.
• noun Costmary.
• noun Water-cress.
• noun In anatomy and zoology, a costa; a pleurapophysis, with or without a hemapophysis; the pleurapophysial element of a vertebra, of whatever size, shape, or mode of connection with a vertebra.
• noun That which resembles a rib in use, position, etc.; a strip, band, or piece of anything when used as a support, or as a member of a framework or skeleton.
• noun Specifically— Some part or organ of an animal like or likened to a rib; a costate or costiform process; a long narrow thickening of a surface; a ridge; a strip or stripe: as, one of the veins or nerves of an insect's wing; one of a set or series of parallel or radiating ridges on a shell; one of the ciliated rays or ctenophores of a ctenophoran.
• noun In ship-building, one of the bent timber or metallic bars which spring from the keel, and form or strengthen the side of the ship.
• noun In architecture: In vaulting, a plain or variously molded and sculptured arch, properly, supporting a vault, or, in combination with other ribs, the filling of a groined vault. In pointed vaults the groins typically rest upon or are covered by ribs; and secondary ribs connecting the main ribs, especially in late and less pure designs, are sometimes applied, usually as a mere decoration, to the plain surfaces of the vaulting-cells. The three main vaulting-ribs are designated as (α) groin-ribs or ogives, (β) doubleaux, and (γ) formerets. (See plan under arc.) Ribs upon the surfaces of the cells are known as surface-ribs. The groin-rib or ogive is also called the diagonal rib, because it occupies the diagonal of the plan of a quadripartite vault. See arch and arc.
• noun An arch-formed piece of timber for supporting the lath-and-plaster work of pseudo-domes, vaults, etc.
• noun In coalmining, a narrow strip or block of solid coal left to support the workings.
• noun One of the curved extension rods on which the cover of an umbrella is stretched.
• noun In botany: One of the principal vascular bundles, otherwise called nerves or veins, into which the primary bundle divides on entering the blade to form the framework of a leaf, commonly salient on its lower surface; a primary nerve: contrasted with vein and veinlet, the branches to which it gives origin. See midrib and nervation. A prominent line on the surface of some other organ, as the fruit.
• noun In cloth or knitted work, a ridge or stripe rising from the groundwork of the material, as in corduroy.
• noun In bookbinding, one of the ridges on the back of a book, which serve for covering the tapes and for ornament.
• noun One of the narrow tracks or ways of iron in which the bed of a printing-press slides to and from impression.
• noun In machinery, an angle-plate cast between two other plates, to brace and strengthen them, as between the sole and wall-plate of a bracket.
• noun In a violin or similar instrument, one of the curved sides of the body, separating the belly from the back.
• noun In gun-making, either of the longitudinally extending upper or lower projections of the metal which join the barrels of a double-barreled gun, and which in fine guns are often ornamented or of ornamental shape. The upper rib is called the top rib; the lower, the bottom rib.
• noun A piece of meat containing one or more ribs; a rib-piece: as, a rib of beef.
• noun A wife: in allusion to Eve, who, according to the account in Genesis, was formed out of one of Adam's ribs.
• noun A strip; a band or ribbon; a long and narrow piece of anything.
• To dress (flax); ripple.
• noun In ceramics, a small piece of wood, leather, or calabash with a straight or curved profile, and usually having a hole in the center for the thumb and finger, used to smooth the surface of a vessel while it is revolving on the wheel. Also called profile or smoother.

from the GNU version of the Collaborative International Dictionary of English.

• transitive verb To furnish with ribs; to form with rising lines and channels.
• transitive verb To inclose, as with ribs, and protect; to shut in.
• transitive verb to leave strips of undisturbed ground between the furrows in plowing.
• noun (Anat.) One of the curved bones attached to the vertebral column and supporting the lateral walls of the thorax.
• noun That which resembles a rib in form or use.
• noun (Shipbuilding) One of the timbers, or bars of iron or steel, that branch outward and upward from the keel, to support the skin or planking, and give shape and strength to the vessel.
• noun (Mach. & Structures) A ridge, fin, or wing, as on a plate, cylinder, beam, etc., to strengthen or stiffen it.
• noun One of the rods on which the cover of an umbrella is extended.