street name vs tropical sweet potato

street name

noun
  • A person’s nickname, such as a gangster or mafia name. 

  • The slang term for a drug, as traded on the streets. 

  • Used other than figuratively or idiomatically: see street, name. 

tropical sweet potato

noun
  • Synonym of name (yam) 

  • Synonym of white sweet potato 

How often have the words street name and tropical sweet potato occurred in a corpus of books? (source: Google Ngram Viewer )