disguised vs under the radar

disguised

adj
  • Wearing a disguise; dressed in strange or unusual clothes, or taking on a changed appearance, especially to conceal one’s identity. 

  • Made to appear as something other than it is, hidden in outward form. 

under the radar

prep
  • Without attracting notice; in an undetected or secretive manner. 

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