labia vs slit

labia

noun
  • The folds of tissue at the opening of the vulva, at either side of the vagina. 

slit

noun
  • The opening of the vagina. 

  • A narrow cut or opening; a slot. 

  • A woman, usually a sexually loose woman; a prostitute. 

adj
  • Having a cut narrow opening 

verb
  • To split into strips by lengthwise cuts. 

  • To cut a narrow opening. 

  • To cut; to sever; to divide. 

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