early on vs undue

early on

adv
  • At an early stage. 

adj
  • Early in a process. 

undue

adj
  • That which ought not to be done; illegal; unjustified. 

  • Not owing or payable. 

  • Excessive; going beyond that what is natural or sufficient. 

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