canal vs drain

canal

verb
  • To dig an artificial waterway in or to (a place), especially for drainage 

  • To travel along a canal by boat 

noun
  • A tubular channel within the body. 

  • An artificial waterway or artificially improved river used for travel, shipping, or irrigation. 

  • One of the faint, hazy markings resembling straight lines on early telescopic images of the surface of Mars. 

drain

verb
  • To convert a perennially wet place into a dry one. 

  • To flow gradually. 

  • To draw off by degrees; to cause to flow gradually out or off; hence, to exhaust. 

  • To deplete of energy or resources. 

  • To fall off the bottom of the playfield. 

  • To cause liquid to flow out of. 

  • To lose liquid. 

noun
  • Something consuming resources and providing nothing in return. 

  • One terminal of a field effect transistor (FET). 

  • An access point or conduit for rainwater that drains directly downstream in a (drainage) basin without going through sewers or water treatment in order to prevent or belay floods. 

  • An outhole. 

  • A conduit allowing liquid to flow out of an otherwise contained volume; a plughole (UK) 

  • An act of urination. 

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