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,
   Sapient.]
   1. The juice of plants of any kind, especially the ascending
      and descending juices or circulating fluid essential to
      nutrition.
      [1913 Webster]

   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.
         [1913 Webster]

   2. The sapwood, or alburnum, of a tree.
      [1913 Webster]

   3. A simpleton; a saphead; a milksop. [Slang]
      [1913 Webster]

   Sap ball (Bot.), any large fungus of the genus Polyporus.
      See 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.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sap \Sap\, v. i.
   To proceed by mining, or by secretly undermining; to execute
   saps. --W. P. Craighill.
   [1913 Webster]

         Both assaults are carried on by sapping. --Tatler.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sap \Sap\, n. (Mil.)
   A narrow ditch or trench made from the foremost parallel
   toward the glacis or covert way of a besieged place by
   digging under cover of gabions, etc.
   [1913 Webster]

   Sap fagot (Mil.), a fascine about three feet long, used in
      sapping, to close the crevices between the gabions before
      the parapet is made.

   Sap roller (Mil.), a large gabion, six or seven feet long,
      filled with fascines, which the sapper sometimes rolls
      along before him for protection from the fire of an enemy.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sap \Sap\, v. t. [imp. & p. p. Sapped; p. pr. & vb. n.
   Sapping.] [F. saper (cf. Sp. zapar, It. zapare), fr. sape a
   sort of scythe, LL. sappa a sort of mattock.]
   1. To subvert by digging or wearing away; to mine; to
      undermine; to destroy the foundation of.
      [1913 Webster]

            Nor safe their dwellings were, for sapped by floods,
            Their houses fell upon their household gods.
                                                  --Dryden.
      [1913 Webster]

   2. (Mil.) To pierce with saps.
      [1913 Webster]

   3. To make unstable or infirm; to unsettle; to weaken.
      [1913 Webster]

            Ring out the grief that saps the mind. --Tennyson.
      [1913 Webster]

WordNet (r) 3.0 (2006):

sap
    n 1: a watery solution of sugars, salts, and minerals that
         circulates through the vascular system of a plant
    2: a person who lacks good judgment [syn: fool, sap,
       saphead, muggins, tomfool]
    3: a piece of metal covered by leather with a flexible handle;
       used for hitting people [syn: blackjack, cosh, sap]
    v 1: deplete; "exhaust one's savings"; "We quickly played out
         our strength" [syn: run down, exhaust, play out,
         sap, tire]
    2: excavate the earth beneath

Moby Thesaurus II by Grady Ward, 1.0:

205 Moby Thesaurus words for "sap":
   abate, abri, approach trench, asshole, attenuate, axiom, babe,
   beverage, blood, blunt, boob, booby, bore, bunker, burrow, center,
   chump, cinch, communication trench, core, countermine, coupure,
   cramp, credulous person, cripple, cull, damp, dampen, deaden,
   debilitate, delve, dematerialize, deplete, destroy, devitalize,
   dig, dig out, dike, ding-a-ling, dingbat, dingdong, disable,
   disembody, distillate, distillation, ditch, double sap, drain,
   dredge, drill, drink, drive, dugout, dull, dupe, easy mark,
   easy pickings, elixir, enervate, enfeeble, entrenchment, essence,
   essential, etherealize, eviscerate, excavate, exhaust, extenuate,
   fabric, fall guy, fire trench, fish, flower, fluid, fluid extract,
   fluid mechanics, flying sap, focus, fool, fortified tunnel, fosse,
   foxhole, fundamental, furrow, gallery, galoot, gist, gobe-mouches,
   goof, gouge, gouge out, gravamen, greener, greenhorn, greeny,
   groove, grub, gruel, gudgeon, gull, heart, honeycomb, hydraulics,
   hydrogeology, hypostasis, inner essence, innocent, jerk, jerk-off,
   juice, kernel, klutz, knock out, latex, lay low, leadpipe cinch,
   liquid, liquid extract, liquor, lower, mark, marrow, material,
   matter, meat, medium, milk, mine, mitigate, moat, monkey, mutt,
   nub, nucleus, nuts and bolts, overset, overthrow, overturn,
   parallel, patsy, pigeon, pith, plaything, postulate, principle,
   prize sap, pushover, quarry, quid, quiddity, quintessence, rarefy,
   rattle, reduce, ruin, sabotage, sap the foundations, saphead,
   sawney, schlemiel, scoop, scoop out, scrabble, scrape, scratch,
   semiliquid, shake, shake up, shovel, sink, sitting duck,
   slit trench, soften up, soul, spade, spirit, spiritualize, stooge,
   stuff, substance, subtilize, subvert, sucker, sum and substance,
   the nitty-gritty, throw down, throw over, toy, trench, trough,
   trusting soul, tunnel, unbrace, undermine, unman, unnerve,
   unstrengthen, unstring, upend, upset, victim, water, weaken, whey,
   wreck



V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

SAP
       Service Access Point (OSI)


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

SAP
       Service Advertising Protocol (Novell, Netware, IPX)


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

SAP
       Session Announcement Protocol (Internet, RFC 2974)


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

SAP
       SIM Access Protocol (mobile-systems, Bluethooth)


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

SAP
       SystemAnalyse und Programmentwicklung (manufacturer, predecessor)


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

SAP
       Symbolic Assembler Program (IBM, IBM 704)


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

SAP
       Systems, Applications and Products [in data processing] [ag]
(manufacturer)


The Free On-line Dictionary of Computing (30 December 2018):

SAP

   1.  SAP AG (Systems, Applications and Products in
   Data Processing).

   2.  Service Advertising Protocol.

   3.  Service Access Point.

   4.  Symbolic Assembler Program.

   (1999-05-26)