clump vs tubercle

clump

noun
  • A small group of trees or plants. 

  • A thick group or bunch, especially of bushes or hair. 

  • A cluster or lump; an unshaped piece or mass. 

  • A dull thud. 

  • A thick addition to the sole of a shoe. 

  • The compressed clay of coal strata. 

verb
  • To gather in dense groups. 

  • To form clusters or lumps. 

  • To walk with heavy footfalls. 

  • To strike; to beat. 

tubercle

noun
  • A small rounded wartlike protuberance of the roots of some leguminous plants; the lip of certain orchids, cacti. 

  • A small rounded nodule forming the characteristic lesion of tuberculosis. 

  • A round nodule, small eminence, or warty outgrowth, especially those found on bones for the attachment of a muscle or ligament or small elevations on the surface of a tooth. 

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