prick vs separatrix

prick

noun
  • An indentation or small mark made with a pointed object. 

  • A small pointed object. 

  • The experience or feeling of being pierced or punctured by a small, sharp object. 

  • The footprint of a hare. 

  • The penis. 

  • Someone (especially a man or boy) who is unpleasant, rude or annoying. 

  • A small roll of yarn or tobacco. 

  • A feeling of remorse. 

  • A small hole or perforation, caused by piercing. 

verb
  • To fix by the point; to attach or hang by puncturing. 

  • To aim at a point or mark. 

  • To incite, stimulate, goad. 

  • To shoot without killing. 

  • To make acidic or pungent. 

  • To drive a nail into (a horse's foot), so as to cause lameness. 

  • To affect with sharp pain; to sting, as with remorse. 

  • To become sharp or acid; to turn sour, as wine. 

  • To pierce or puncture slightly. 

  • To make or become sharp; to erect into a point; to raise, as something pointed; said especially of the ears of an animal, such as a horse or dog; and usually followed by up. 

  • To form by piercing or puncturing. 

  • To mark the surface of (something) with pricks or dots; especially, to trace a ship’s course on (a chart). 

  • Usually in the form prick out: to plant (seeds or seedlings) in holes made in soil at regular intervals. 

separatrix

noun
  • The proofreader's mark resembling a slash ⟨ / ⟩ or vertical bar ⟨ | ⟩ placed after a note in the margin to indicate that it should replace the item(s) struckthrough in the running text or to separate it from other margin notes. 

  • The ⟨L⟩ or pipe ⟨|⟩ mark formerly used to divide integers from decimals. 

  • The line between regions having different magnetic fields. 

  • The boundary separating two modes of behavior in a differential equation. 

  • A terminator: a line on a partially-illuminated surface separating the lit and shaded regions. 

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