hachure vs hatching

hachure

noun
  • A line on a map indicating the steepness of a slope. 

verb
  • To mark a map with hachures. 

hatching

noun
  • A method of shading areas of a drawing or diagram with fine parallel lines. 

  • A group of birds, reptiles, fish, insects, etc., which emerge from their eggs at the same time. 

  • Patterns used in construction drawings to represent various materials. 

  • The act of an egg hatching, eclosion 

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