mind-numbing vs plodding

mind-numbing

adj
  • Excessively boring, tedious, or dull; repetitive; of an activity, etc., lacking any interest or variety that might serve as intellectual stimulation. 

plodding

adj
  • Progressing slowly and laboriously. 

noun
  • Slow, laborious progress. 

How often have the words mind-numbing and plodding occurred in a corpus of books? (source: Google Ngram Viewer )