The whitish inner portion of the rind of citrus fruits that is a source of pectin, commonly referred to as the pith.
The fraction of incident light or radiation reflected by a surface or body, commonly expressed as a percentage.
One of the four major stages of the magnum opus, involving purification of the prima materia.
The soft inner part of something, especially the pith of a fruit.
The medulla oblongata.
The internal tissue of a plant.
The inner substance of various organs and structures, especially the marrow of bones.