cowslip tea vs hashish

cowslip tea

noun
  • An herbal tea made with cowslip flowers. 

hashish

noun
  • A cannabis extract. 

  • Marijuana generally. 

  • The leaves and tender parts of the Indian hemp plant (which are intoxicating), which are dried for either chewing or smoking. 

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