ass-licker vs brown noser

ass-licker

noun
  • Someone who succumbs to authority, doing whatever authority figures ask and attempting to please them in every possible way. 

  • Someone who performs anilingus. 

brown noser

noun
  • One who brownnoses (flatters or humors somebody in an obsequious manner for personal gain); one who sucks up; a bootlicker, ass-kisser, sycophant. 

How often have the words ass-licker and brown noser occurred in a corpus of books? (source: Google Ngram Viewer )