Definition of "sap"

sap¹

/sæp/

noun
countable and uncountable, plural saps
1. (uncountable) The juice of plants of any kind, especially the ascending and descending juices or circulating fluid essential to nutrition.
2. (uncountable) The sapwood, or alburnum, of a tree.
3. Any juice.
4. (figurative) Vitality.
5. (slang, countable) A naive person; a simpleton.
  Quotations
  She said I'm such a sap, I'm such a jerk / Can't I ever forget the way that we are / Spend all your time with your eyes on the ground / Looking for the stars
  1997, “Don't Look Down”, in Curtains, performed by Tindersticks
verb
third-person singular simple present saps, present participle sapping, simple past and past participle sapped
1. (transitive) To drain, suck or absorb from (tree, etc.).
2. (transitive, figurative) To exhaust the vitality of.
  Quotations
  While Tuchel will be delighted with the way his players responded, there will be concern at how much the energy-sapping 120 minutes has taken out of them.
  2022 April 12, Neil Johnston, “Real Madrid 2-3 Chelsea”, in BBC Sport‎

sap²

/sæp/

noun
plural saps
1. (countable, US, slang) A short wooden club; a leather-covered hand weapon; a blackjack.
  Quotations
  I risk my whole future, the hatred of the cops and Eddie Mars' gang. I dodge bullets and eat saps.
  1944, William Faulkner, Leigh Brackett, Jules Furthman, The Big Sleep (screenplay)
verb
third-person singular simple present saps, present participle sapping, simple past and past participle sapped
1. (transitive, slang) To strike with a sap (with a blackjack).
  Quotations
  [A]s he passes the mouth of a narrow alley two men step out quickly. One of them saps Marlowe expertly — they drag him out of sight.
  1944, William Faulkner, Leigh Brackett, Jules Furthman, The Big Sleep (screenplay)
  And when he had me up there he would sap me again and I wouldn't remember anything that happened in between the two sappings.
  1964, Raymond Chandler, Killer in the Rain

sap³

/sæp/

noun
plural saps
1. (military) 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.
verb
third-person singular simple present saps, present participle sapping, simple past and past participle sapped
1. (transitive) To subvert by digging or wearing away; to mine; to undermine; to destroy the foundation of.
  Quotations
  Nor safe their dwellings were, for sapped by floods, / Their houses fell upon their household gods.
  1717, John Dryden [et al.], “(please specify |book=I to XV)”, in Ovid’s Metamorphoses in Fifteen Books. […], London: […] Jacob Tonson, […]
2. (transitive, military) To pierce with saps.
3. (transitive) To make unstable or infirm; to unsettle; to weaken.
  Quotations
  Ring out the grief that saps the mind […]
  1850, Alfred Tennyson, Ring, Out, Wild Bells
4. (transitive) To gradually weaken.
5. (intransitive) To proceed by mining, or by secretly undermining; to execute saps.