ruminate vs sweat over

ruminate

verb
  • To meditate or reflect. 

  • To meditate or ponder over; to muse on. 

  • To chew cud. (Said of ruminants.) Involves regurgitating partially digested food from the rumen. 

adj
  • Having a hard albumen penetrated by irregular channels filled with softer matter, as the nutmeg and the seeds of the North American papaw. 

sweat over

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