thwart vs unchancy

thwart

verb
  • To cause to fail; to frustrate, to prevent. 

adj
  • Placed or situated across something else; cross, oblique, transverse. 

noun
  • A seat across a boat on which a rower may sit. 

  • An act of thwarting; something which thwarts; a hindrance, an obstacle. 

  • A brace, perpendicular to the keel, that helps maintain the beam (“breadth”) of a marine vessel against external water pressure and that may serve to support the rail. 

unchancy

adj
  • Unfortunate, unlucky. 

  • Dangerous, unsafe. 

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