shrewd vs sly as a fox

shrewd

adj
  • Artful, tricky or cunning. 

  • Sharp, snithy, piercing. 

  • Showing clever resourcefulness in practical matters. 

  • Streetwise, street-smart. 

  • Knowledgeable, intelligent, keen. 

  • Nigh accurate. 

  • Severe, intense, hard. 

sly as a fox

adj
  • Very sly, very cunning. 

How often have the words shrewd and sly as a fox occurred in a corpus of books? (source: Google Ngram Viewer )