ineffectual vs null and void

ineffectual

adj
  • Worthless; ineffective. 

  • Unable or insufficient to produce effect. 

  • Weak, indecisive; lacking forcefulness. 

null and void

adj
  • invalid, cancelled, unenforceable 

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