thorough vs thoughtless

thorough

adj
  • Utter; complete; absolute. 

  • Painstaking and careful not to miss or omit any detail. 

noun
  • A furrow between two ridges, to drain off the surface water. 

thoughtless

adj
  • Lacking thought or consideration. 

  • Marked by or showing lack of due thought or care; careless. 

  • Inconsiderate, inattentive. 

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