support resembling the rib of an animal
"The architect designed the roof with a series of curved ribs to provide structural strength."
cut of meat including one or more ribs
"The butcher sliced a large roast into individual cuts, selecting a rib to serve as the main course."
a teasing remark
"His friend gave him a rib about his terrible singing voice during the karaoke night."
a riblike supporting or strengthening part of an animal or plant
"The ancient ship's hull was reinforced with wooden ribs to prevent it from warping under heavy loads."
a projecting molding on the underside of a vault or ceiling; may be ornamental or structural
"The Gothic cathedral features delicate stone ribs running across the underside of its soaring barrel vault to provide both support and decoration."
Rigid inflatable boat — A lightweight inflatable boat with a rigid hull.
"The hound's-tongue, locally known as rib, is a poisonous plant that grows in damp meadows."
Any of a series of long curved bones occurring in 12 pairs in humans and other animals and extending from the spine to or toward the sternum.
Hound's-tongue (Cynoglossum officinale).
In plain English: A rib is any of the curved bones that form your chest cage and protect your heart and lungs.
"She took a deep breath and felt her ribs expand with air."
Usage: Use "rib" as a noun to refer specifically to one of the curved bones connecting your spine and chest wall. As a verb, it means to reinforce something by adding such structural supports or ridges.
To shape, support, or provide something with a rib or ribs.
"The carpenter ribbed the wooden panel to add strength before painting it."
In plain English: To rib someone means to tease them playfully by making fun of their mistakes or quirks in a friendly way.
"The coach ribbed his teammate for missing such an easy shot."
The word "rib" comes from Old English ribb, which traces back to a Proto-Indo-European root meaning "arch, ceiling, or cover." It entered Middle English with essentially the same physical sense it holds today.