Pith is soft and spongy material in plant stems and the core of animal bones, or the white tissue lining the rind of an orange, lemon or other citrus fruit.(noun)
An example of pith is the spongy material found inside plant stems.
See pith in Webster's New World College Dictionary
Origin: ME pithe < OE pitha, akin to MDu pitte, pit of a fruit, kernel, pith of a tree
See pith in American Heritage Dictionary 4
Origin: Middle English
Origin: , from Old English pitha.
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