aqueduct vs tideway

aqueduct

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

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

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

tideway

noun
  • A channel in which the tide sets. 

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