The cat's p*jamas

Papagena (without pyjamas, -- or legs, apparently)

A Canadian twitter follower of mine recently asked which is the correct spelling: pyjamas or pajamas. Traditionally Canadians have followed the British in using "pyjamas" whereas Americans use "pajamas". She felt (and lamented) that Canadians were "sliding" into American usage on this. When we edited the Canadian Oxford Dictionary, "pyjamas" was definitely more common, but this comment suggested it was time to look into it again, so I conducted a facebook poll. So far, 37 Canadians have answered "pyjamas" versus only 6 saying "pajamas", so I don't think much sliding is going on. If you're Canadian and haven't participated in my facebook poll, let me know what spelling you use in the comments (or send me an email).

This is one of the many words that the English borrowed during their time in India. It comes from the Urdu pāy-jāma, pā-jāma, (in turn coming from Persian pāy , pā foot, leg + jāma clothing, garment) and originally designated the loose floaty trousers worn in the Indian subcontinent. The English adopted these as sleepwear in the 19th century, and combined them with a light jacket. As you can see, there is no -s ending in the original language: it was added in English by analogy with "trousers", "pants", etc. 

Intriguingly, until the early 20th century, this word was apparently pronounced "pie jamma" 

As for the phrase "the cat's pyjamas", we do not know what wit thought it up, but it cropped up, along with its variants "cat's whiskers" and "cat's meow", or -- my father's favourite -- "cat's ass" in the 1920s,