cylindrical vs discoid

cylindrical

adj
  • Shaped like a cylinder. 

  • Describing a map projection in which meridians are mapped onto vertical lines and parallels of latitude onto horizontal lines. 

discoid

adj
  • Shaped like a disc/disk. 

noun
  • A disk-shaped dental excavator designed to remove the carious dentin of a decayed tooth 

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