(noun) a riblike part of a plant or animal (such as a middle rib of a leaf or a thickened vein of an insect wing)
(noun) any of the 12 pairs of curved arches of bone extending from the spine to or toward the sternum in humans (and similar bones in most vertebrates)
Definitions for Sunspot
(noun) a cooler darker spot appearing periodically on the sun's photosphere; associated with a strong magnetic field