What is the origin or the word pajamas?

The term 'pajamas' or 'pyjamas' comes from Hindi, 'pajama', from Urdu, describing loose trousers gathered with a drawstring tie at the waist; it is believed to have come to India from the Persian 'paejamah', or 'leg clothing'.

The garment, worn by Muslims in India, was copied by Europeans working in India, and is originally recorded in English in 1800 as 'pai jamahs' or 'pay jamah'.

Today's US-English spelling dates from the mid-nineteenth century.