sap 1
/sap/ , n. , v. , sapped, sapping .
n.
1. the juice or vital circulating fluid of a plant, esp. of a woody plant.
2. any vital body fluid.
3. energy; vitality.
4. sapwood.
5. Slang. a fool; dupe.
6. Metall. soft metal at the core of a bar of blister steel.
v.t.
7. to drain the sap from.
[ bef. 900; ME; OE saep; c. D sap; akin to G Saft juice, ON safi; in def. 5 a shortening of SAPHEAD ]
sap 2
/sap/ , n. , v. , sapped, sapping .
n.
1. Fort. a deep, narrow trench constructed so as to form an approach to a besieged place or an enemy's position.
v.t.
2. Fort.
a. to approach (a besieged place or an enemy position) by means of deep, narrow trenches protected by gabions or parapets.
b. to dig such trenches in (ground).
3. to undermine; weaken or destroy insidiously.
v.i.
4. Fort. to dig a sap.
[ 1585-95; sape (n.), deriv. of saper to dig a trench zappare, a military term, based on zappa hoe (cf. dial. It zappo he-goat ]
Syn. 3. impair, enfeeble, deplete, exhaust, enervate.