garment vs tunic

garment

noun
  • A single item of clothing. 

  • The visible exterior in which a thing is invested or embodied. 

verb
  • To clothe in a garment. 

tunic

noun
  • A garment worn over the torso, with or without sleeves, and of various lengths reaching from the hips to the ankles. 

  • Any covering, such as seed coat or the organ that covers a membrane. 

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