metropolis vs slub

metropolis

noun
  • A large, busy city, especially as the main city in an area or country or as distinguished from surrounding rural areas. 

  • The mother (founding) polis (city state) of a colony. 

  • The see of a metropolitan bishop, ranking above its suffragan diocesan bishops. 

  • A generic focus in the distribution of plants or animals. 

slub

verb
  • To draw and twist fibers in order to prepare them for spinning. 

noun
  • Fabric fiber produced by slubbing. 

  • A small thickened portion or knot found on linen yarn, caused by defects. 

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