The Collaborative International Dictionary of English v.0.48:
Sap \Sap\, n. [AS. saep; akin to OHG. saf, G. saft, Icel. safi;
of uncertain origin; possibly akin to L. sapere to taste, to
be wise, sapa must or new wine boiled thick. Cf. Sapid,
1. The juice of plants of any kind, especially the ascending
and descending juices or circulating fluid essential to
Note: The ascending is the crude sap, the assimilation of
which takes place in the leaves, when it becomes the
elaborated sap suited to the growth of the plant.
2. The sapwood, or alburnum, of a tree.
3. A simpleton; a saphead; a milksop. [Slang]
Sap ball (Bot.), any large fungus of the genus Polyporus.
Sap green, a dull light green pigment prepared from the
juice of the ripe berries of the Rhamnus catharticus, or
buckthorn. It is used especially by water-color artists.
Sap rot, the dry rot. See under Dry.
Sap sucker (Zool.), any one of several species of small
American woodpeckers of the genus Sphyrapicus,
especially the yellow-bellied woodpecker (Sphyrapicus
varius) of the Eastern United States. They are so named
because they puncture the bark of trees and feed upon the
sap. The name is loosely applied to other woodpeckers.
Sap tube (Bot.), a vessel that conveys sap.