deadhead vs sap

deadhead

noun
  • A stupid or boring person; dullard. 

  • An employee of a transport company, especially a pilot, traveling as a passenger for logistical reasons, for example to return home or travel to the next assignment. 

  • A train or truck moved between cities with no passengers or freight, in order to make it available for service. 

  • A person staying at a lodging, such as a hotel or boarding house, without paying rent; freeloader. 

  • A person either admitted to a theatrical or musical performance without charge, or paid to attend. 

  • Anyone traveling for free. 

  • A tree or tree branch fixed in the bottom of a river or other navigable body of water, partially submerged or rising nearly the surface, by which boats are sometimes pierced and sunk; snag. 

  • A zombie. 

  • Driftwood. 

verb
  • To travel as a deadhead, or non-paying passenger. 

  • To drive an empty vehicle. 

  • To send (a person or message) for free. 

  • To remove spent or dead blossoms from a plant. 

  • To admit to a performance without charge. 

sap

noun
  • A naive person; a simpleton 

  • 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. 

  • The sapwood, or alburnum, of a tree. 

  • The juice of plants of any kind, especially the ascending and descending juices or circulating fluid essential to nutrition. 

  • Vitality. 

  • Any juice. 

  • A short wooden club; a leather-covered hand weapon; a blackjack. 

verb
  • To subvert by digging or wearing away; to mine; to undermine; to destroy the foundation of. 

  • To proceed by mining, or by secretly undermining; to execute saps. 

  • To make unstable or infirm; to unsettle; to weaken. 

  • To gradually weaken. 

  • To strike with a sap (with a blackjack). 

  • To exhaust the vitality of. 

  • To pierce with saps. 

  • To drain, suck or absorb from (tree, etc.). 

How often have the words deadhead and sap occurred in a corpus of books? (source: Google Ngram Viewer )