fly ball vs housefly

fly ball

noun
  • A batted ball that has been hit into the air above the outfield; a fly. 

  • A geek; beatnik. 

housefly

noun
  • Any fly regularly found in human dwellings. 

  • The common housefly, Musca domestica, that frequents most homes and spreads some diseases. 

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