cough drop vs lozenge

cough drop

noun
  • A small, medicated tablet intended to be dissolved slowly in the mouth to relieve coughing symptoms temporarily. 

lozenge

noun
  • A small tablet (originally diamond-shaped) or medicated sweet used to ease a sore throat. 

  • A quadrilateral with sides of equal length (rhombus), having two acute and two obtuse angles. 

verb
  • To mark or emblazon with a lozenge. 

  • To form into the shape of a lozenge. 

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