dog-ear vs plicate

dog-ear

verb
  • To fold (the corner of the page of a book or other publication). 

noun
  • The folded corner of the page of a book or other publication, either due to having been read many times or intentionally as a sort of bookmark. 

plicate

verb
  • To fold or pleat (usually used in passive). 

adj
  • Folded multiple times lengthwise like a fan, usually lending stiffness to a flat structure such as a leaf; corrugated; pleated. 

How often have the words dog-ear and plicate occurred in a corpus of books? (source: Google Ngram Viewer )