noun (1)
\ ˈsap How to pronounce sap (audio) \

Definition of sap

 (Entry 1 of 4)

1a : the fluid part of a plant specifically : a watery solution that circulates through a plant's vascular system
b(1) : a body fluid (such as blood) essential to life, health, or vigor
(2) : bodily health and vigor
2 : a foolish gullible person
3 [probably short for sapling] : blackjack, bludgeon


verb (1)
sapped; sapping

Definition of sap (Entry 2 of 4)

transitive verb

1 : to drain or deprive of sap
2 : to knock out with a sap


verb (2)
sapped; sapping

Definition of sap (Entry 3 of 4)

intransitive verb

: to proceed by digging a sap

transitive verb

1 : to subvert by digging or eroding the substratum or foundation : undermine
2a : to gradually diminish the supply or intensity of sapped her strength
b : to weaken or exhaust the energy or vitality of the illness sapped him of his stamina
3 : to operate against or pierce by a sap


noun (2)

Definition of sap (Entry 4 of 4)

: the extension of a trench to a point beneath an enemy's fortifications

Other Words from sap

Noun (1)

sapless \ ˈsa-​pləs How to pronounce sap (audio) \ adjective
saplessness \ ˈsa-​pləs-​nəs How to pronounce sap (audio) \ noun

Choose the Right Synonym for sap

Verb (2)

weaken, enfeeble, debilitate, undermine, sap, cripple, disable mean to lose or cause to lose strength or vigor. weaken may imply loss of physical strength, health, soundness, or stability or of quality, intensity, or effective power. a disease that weakens the body's defenses enfeeble implies a condition of marked weakness and helplessness. enfeebled by starvation debilitate suggests a less marked or more temporary impairment of strength or vitality. the debilitating effects of surgery undermine and sap suggest a weakening by something working surreptitiously and insidiously. a poor diet undermines your health drugs had sapped his ability to think cripple implies causing a serious loss of functioning power through damaging or removing an essential part or element. crippled by arthritis disable suggests bringing about impairment or limitation in a physical or mental ability. disabled by an injury sustained at work

First Known Use of sap

Noun (1)

before the 12th century, in the meaning defined at sense 1a

Verb (1)

1725, in the meaning defined at sense 1

Verb (2)

1598, in the meaning defined at intransitive sense

Noun (2)

1642, in the meaning defined above

History and Etymology for sap

Noun (1)

Middle English, from Old English sæp; akin to Old High German saf sap

Verb (2)

Middle French sapper, from Old Italian zappare, from zappa hoe

Noun (2)

French sape, from saper

Learn More About sap

Time Traveler for sap

Time Traveler

The first known use of sap was before the 12th century

See more words from the same century

Dictionary Entries Near sap

São Vicente, Cabo de



See More Nearby Entries 

Statistics for sap

Cite this Entry

“Sap.” Dictionary, Merriam-Webster, Accessed 6 Oct. 2022.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

More Definitions for sap


\ ˈsap How to pronounce sap (audio) \

Kids Definition of sap

 (Entry 1 of 2)

: a watery juice that circulates through a plant and carries food and nutrients


sapped; sapping

Kids Definition of sap (Entry 2 of 2)

: to weaken or use up little by little … the heavy load they dragged sapped their strength severely.— Jack London, The Call of the Wild


Medical Definition of sap

More from Merriam-Webster on sap

Nglish: Translation of sap for Spanish Speakers

Britannica English: Translation of sap for Arabic Speakers Encyclopedia article about sap


Test Your Vocabulary

Challenging Words You Should Know

  • hedgehog reading a book
  • Often used to describe “the march of time,” what does inexorable mean?
Spell It

Can you spell these 10 commonly misspelled words?

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!