pajamas vs pyjamas

pajamas

noun
  • Loose-fitting trousers worn by both sexes in various southern Asian countries including India. 

  • Clothes for wearing to bed and sleeping in, usually consisting of a loose-fitting shirt and pants/trousers. 

pyjamas

noun
  • Britain standard spelling of pajamas (loose trousers worn by men and women in South Asia). 

  • Britain standard spelling of pajamas (clothes for sleeping in). 

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