plain vs swale

plain

noun
  • An expanse of land with relatively low relief, usually exclusive of forests, deserts, and wastelands. 

  • A lamentation. 

adj
  • Downright; total, unmistakable (as intensifier). 

  • Clear; unencumbered; equal; fair. 

  • Not a trump. 

  • Containing no extended or nonprinting characters (especially in plain text). 

  • Not unusually beautiful; unattractive. 

  • Evident to one's senses or reason; manifest, clear, unmistakable. 

  • Honest and without deception; candid, open; blunt. 

  • Simple in habits or qualities; unsophisticated, not exceptional, ordinary. 

  • Ordinary; lacking adornment or ornamentation; unembellished. 

  • Having only few ingredients, or no additional ingredients or seasonings; not elaborate, without toppings or extras. 

  • Of just one colour; lacking a pattern. 

adv
  • Simply. 

swale

noun
  • A low tract of moist or marshy land. 

  • A long narrow and shallow trough between ridges on a beach, running parallel to the coastline. 

  • Bioswale, a shallow trough dug into the land on contour (horizontally with no slope), whose purpose is to allow water time to percolate into the soil. 

  • A shallow, usually grassy depression sloping downward from a plains upland meadow or level vegetated ridgetop. 

  • A gutter in a candle. 

  • A shallow troughlike depression that's created to carry water during rainstorms or snow melts; a drainage ditch. 

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