slap bang vs spang

slap bang

adv
  • Exactly, precisely 

spang

verb
  • To set with bright points: star or spangle. 

  • To hitch; fasten. 

  • To cause to spring; set forcibly in motion; throw with violence. 

  • To strike or ricochet with a loud report 

  • To leap; spring. 

noun
  • A bound or spring; a leap. 

  • A span. 

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