erroneous vs ungrounded

erroneous

adj
  • Mistaken. 

  • Derived from an error. 

  • Containing an error; inaccurate. 

  • Deviating from the requirements of the law, but without a lack of legal authority, thus not illegal. 

ungrounded

adj
  • Not grounded; without ground or basis, unreal, false. 

  • Not connected to ground potential 

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