bootlicker vs brown noser

bootlicker

noun
  • A person who behaves in a servile or obsequious manner; a toady 

  • Anyone who is seen as supporting authoritarianism. 

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 bootlicker and brown noser occurred in a corpus of books? (source: Google Ngram Viewer )