irreflective vs regardless

irreflective

adj
  • Without mental reflection. 

regardless

adj
  • Having no regard; heedless; careless. 

  • despite everything; despite the situation 

adv
  • Without attention to warnings or indications of bad consequences. 

prep
  • Synonym of regardless of; paying no attention to 

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