pith

The soft, spongy tissue in the center of the stems of most vascular plants, consisting mainly of parenchyma.

The soft inner substance of a feather or hair.

The spinal cord.

The essential or central part; the heart or essence.

Strength; vigor; mettle.

Significance; importance.

To remove the pith from (a plant stem).

To sever or destroy the spinal cord of, usually by inserting a needle into the vertebral canal.

To kill (cattle) by cutting the spinal cord.