odorant vs smelly

odorant

adj
  • Having an odour/odor. 

noun
  • Any substance that has a distinctive smell, especially one added to something (such as household gas) for safety purposes 

smelly

adj
  • Having a bad smell. 

  • Having signs that suggest a design problem; having a code smell. 

  • Having a quality that arouses suspicion. 

noun
  • a Short Magazine Lee Enfield rifle or one of its derivatives. 

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