Definitions
1.nounThe soft, spongy substance in the center of the stems of many plants and trees.
2.nounThe spongy interior substance of a feather or horn.
3.nounThe spinal cord; the marrow.
4.nounThe albedo of a citrus fruit.
5.nounThe essential or vital part; force; energy; importance."The pith of my idea is that people should choose their own work hours."
6.nounPower, strength, might.
7.verbTo extract the pith from (a plant stem or tree).
8.verbTo kill (especially cattle or laboratory animals) by cutting or piercing the spinal cord.