rude vs surd

rude

adj
  • Lacking refinement or skill; untaught; ignorant; raw. 

  • Violent; abrupt; turbulent. 

  • Somewhat obscene, pornographic, offensive. 

  • Lacking in refinement or civility; bad-mannered; discourteous. 

  • Undeveloped, unskilled, inelegant. 

  • Hearty, vigorous; found particularly in the phrase rude health. 

  • Crudely made; primitive. 

surd

adj
  • unvoiced; voiceless 

  • Involving surds, or irrational numbers; not capable of being expressed in rational numbers. 

noun
  • An irrational number, especially one expressed using the √ symbol. 

  • A voiceless consonant. 

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