pith

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Botany The soft, spongelike, central cylinder of the stems of most flowering plants, composed mainly of parenchyma.
2. n. Zoology The soft inner substance of a feather or hair.
3. n. The essential or central part; the heart or essence. See Synonyms at substance.
4. n. Strength; vigor; mettle.
5. n. Significance; importance.
6. n. Archaic Spinal cord or bone marrow.
7. v. To remove the pith from (a plant stem).
8. v. To sever or destroy the spinal cord of, usually by inserting a needle into the vertebral canal.
9. v. To kill (cattle) by cutting the spinal cord.

Century Dictionary and Cyclopedia

1. n. In botany, the medulla, or central cylinder, composed of typical parenchymatous tissue, which occupies the center of the stems of dicotyledonous plants. By Gris the cells of pith have been divided into
2. n. In. anatomy: The spinal cord or marrow; the medulla spinalis.
3. n. The central or medullary core of a hair.
4. n. Strength; vigor; force.
5. n. Energy; concentrated force; closeness and vigor of thought and style.
6. n. Condensed substance or matter; quintessence.
7. n. Weight; moment; importance.
8. To introduce an instrument into the cranial or spinal cavity of (an animal, as a frog), and destroy the cerebrospinal axis or a part of it.
9. n. The soft interior portion of the shaft of a feather.

Wiktionary

1. n. The soft spongy substance in the center of the stems of many plants and trees.
2. n. figuratively The essential or vital part.
3. v. transitive To extract the pith from (a plant stem or tree).
4. v. transitive To kill (especially cattle or laboratory animals) by cutting or piercing the spinal cord.

GNU Webster's 1913

1. n. (Bot.) The soft spongy substance in the center of the stems of many plants and trees, especially those of the dicotyledonous or exogenous classes. It consists of cellular tissue.
2. n. (Zoöl.) The spongy interior substance of a feather.
3. n. (Anat.) The spinal cord; the marrow.
4. n. Hence: The which contains the strength of life; the vital or essential part; concentrated force; vigor; strength; importance.
5. v. (Physiol.) To destroy the central nervous system of (an animal, as a frog), as by passing a stout wire or needle up and down the vertebral canal.

WordNet 3.0

1. n. the choicest or most essential or most vital part of some idea or experience
2. n. soft spongelike central cylinder of the stems of most flowering plants
3. v. remove the pith from (a plant)