ass-kissing vs fawning

ass-kissing

noun

  • The practice of kissing ass; flattery; obsequious behavior. 

fawning

noun

  • Servile flattery. 

adj

  • Seeking favor by way of flattery; flattering, servile. 

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