molar vs premolar

molar

adj
  • Of or relating to the molar teeth, or to grinding. 

  • Of, relating to, or being a solution containing one mole of solute per litre of solution. 

  • Of or relating to a complete body of matter as distinct from its molecular or atomic constituents. 

noun
  • A unit of concentration equal to one mole per litre. 

  • A back tooth having a broad surface used for grinding one's food. 

premolar

adj
  • Before a molar tooth, either in physical position or in its time of development; deciduous. 

noun
  • A tooth situated in front of the molar teeth; especially a tooth in humans with two cusps which is between the canines and the molars (Latin: singular dens premolaris, plural dentes premolares) 

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