boff vs slap

boff

verb
  • To hit; to strike. 

  • to have sexual intercourse (with someone) 

noun
  • A great success; a hit. 

  • A pupil who works hard; a swot. 

  • A line in a film etc that elicits such a laugh. 

  • A big laugh. 

  • A hit or smack. 

slap

verb
  • To strike soundly against something. 

  • To impose a penalty, etc. on (someone). 

  • To play slap bass on (an instrument). 

  • To be excellent. 

  • To cause something to strike soundly. 

  • To place, to put carelessly. 

  • To give a slap to. 

adv
  • Exactly, precisely 

noun
  • The percussive sound produced in slap bass playing. 

  • An eye-catching sticker used in street art. 

  • Makeup; cosmetics. 

  • A blow, especially one given with the open hand, or with something broad and flat. 

  • A sharp percussive sound like that produced by such a blow. 

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