aqueduct vs canyon

aqueduct

noun
  • A structure carrying water over a river or depression, especially in regards to ancient aqueducts. 

  • An artificial channel that is constructed to convey water from one location to another. 

  • A structure conveying fluid, such as the cerebral aqueduct or vestibular aqueduct. 

canyon

noun
  • A valley, especially a long, narrow, steep valley, cut in rock by a river. 

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