single-hearted vs zealous

single-hearted

adj
  • Devoted; unambivalent and dedicated. 

  • Having an honest heart; straightforward, free from duplicity. 

zealous

adj
  • Full of zeal; ardent, fervent; exhibiting enthusiasm or strong passion. 

How often have the words single-hearted and zealous occurred in a corpus of books? (source: Google Ngram Viewer )