sap

¹ American  

[sap] / sæp /

noun

1. the juice or vital circulating fluid of a plant, especially of a woody plant.

2. any vital body fluid.

3. energy; vitality.

4. sapwood.

5. Slang. a fool; sucker; dupe.

6. Metallurgy. soft metal at the core of a bar of blister steel.

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verb (used with object)

sapped, sapping

1. to drain the sap from.

sap ² American  

[sap] / sæp /

noun

1. Fortification. a deep, narrow trench constructed so as to form an approach to a besieged place or an enemy's position.

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verb (used with object)

sapped, sapping

1. to undermine; gradually or insidiously weaken or destroy.

   Synonyms:

   undermine, weaken, tire, impair, exhaust, enfeeble, enervate, drain, deplete

2. Fortification.

   1. to approach (a besieged place or an enemy position) by means of deep, narrow trenches protected by gabions or parapets.

   2. to dig such trenches in (ground).

verb (used without object)

sapped, sapping

1. Fortification. to dig a sap.

sap ³ American  

[sap] / sæp /

noun

1. a short club with a heavy tip that is used as a weapon; blackjack; bludgeon.

   The burglar carried a set of lockpicks and a sap.

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verb (used with object)

1. to hit (someone) with a club.

   If he tries to sneak out, I'll sap him over the head.

sap ¹ British  

/ sæp /

noun

1. a solution of mineral salts, sugars, etc, that circulates in a plant

2. any vital body fluid

3. energy; vigour

4. slang a gullible or foolish person

5. another name for sapwood

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verb

1. to drain of sap

SAP ² British  

abbreviation

1. South African Police

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SAP ³ British  

/ sæp /

acronym

1. Standard Assessment Procedure, the recognized performance indicator for measuring energy efficiency in buildings

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sap ⁴ British  

/ sæp /

noun

1. a deep and narrow trench used to approach or undermine an enemy position, esp in siege warfare

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verb

1. to undermine (a fortification, etc) by digging saps

2. (tr) to weaken

sap Scientific  

/ săp /

1. The watery fluid that circulates through a plant that has vascular tissues. Sap moving up the xylem carries water and minerals, while sap moving down the phloem carries water and food.

2. See cell sap

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Other Word Forms

• sapless adjective

Etymology

Origin of sap¹

First recorded before 900; Middle English; Old English sæp; cognate with Dutch sap; akin to German Saft juice, Old Norse safi; sap ¹ in def. 5 a shortening of saphead

Origin of sap²

First recorded in 1585–95; from French noun sape “spade, spadework,” derivative of saper “to dig a trench,” from Italian zappare “to undermine,” a military term, based on zappa “hoe”

Origin of sap³

First recorded in 1895–1900; perhaps shortening of sapling or sapwood (used as a tool or weapon)

Example Sentences

Travel-related companies have weathered investor fears that the war with Iran would sap demand for leisure travel.

From MarketWatch • Mar. 23, 2026

I think they’re doing so not only because they’re personally disgusted, but because they agree with Judge McKeown that this behavior will eventually sap their authority as a court.

From Slate • Mar. 13, 2026

Most kithul-producing households divide labour the same way -- husbands collect the sap while the wives process it into sweets.

From Barron's • Feb. 10, 2026

All five patients had recently consumed raw date palm sap, a sweet liquid commonly collected during winter and frequently visited by bats.

From Science Daily • Feb. 1, 2026

There is a big bonfire under the kettle, and the sap boils, and Grandpa watches it carefully.

From "Little House in the Big Woods" by Laura Ingalls Wilder

Related Words

• blunt
• deplete
• destroy
• drain
• erode
• exhaust
• impair
• ruin
• undermine
• vitiate
• wreck