chillum vs clay pipe

chillum

noun
  • The part of such a pipe that contains the tobacco and charcoal balls. 

  • A conical pipe used for smoking marijuana, usually made of fired clay, porcelain, soapstone, glass or, more rarely, wood. 

clay pipe

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