amend vs weaken

amend

verb
  • To become better. 

  • To make better; improve. 

  • To make a formal alteration (in legislation, a report, etc.) by adding, deleting, or rephrasing. 

noun
  • An act of righting a wrong; compensation. 

weaken

verb
  • To become weaker or less strong. 

  • To make weaker or less strong. 

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