birthday suit vs nude

birthday suit

noun
  • Nakedness, unclothed skin; an exposure of a human's natural anatomy without clothing. 

  • Used other than figuratively or idiomatically: see birthday, suit. 

nude

noun
  • The state of total nudity. 

  • A color that resembles or evokes bare flesh; a paint, dye, etc. of such color. 

  • A painting, sculpture, photograph or other artwork or mass-media-reproduced image depicting one or more human figure(s) in a state of near or total undress. 

adj
  • Without clothing or other covering of the skin; without clothing on the genitals or female nipples. 

  • Of a color (such as beige or tan) that evokes bare flesh. 

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