ass-licking vs sycophancy

ass-licking

noun

  • Sycophancy. 

  • Anilingus. 

sycophancy

noun

  • The fawning behavior of a sycophant; servile flattery; fawningness. 

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