Pajamas and pyjamas both mean the same loose, comfortable clothing worn for sleeping. Pajamas is the American spelling; pyjamas, with a y instead of an a in the second syllable, is the British spelling. Both trace back to a Persian word for a leg garment.
The core difference
Pajamas and pyjamas are the same word with an American and a British spelling.
- pajamas — American spelling: He answered the door still in his pajamas.
- pyjamas — British spelling: He came downstairs still in his pyjamas.
How to tell them apart
Both spellings ultimately come from Hindustani, which took the word from Persian pāy (leg) and jāma (garment). The word originally described loose trousers before it came to mean sleepwear more broadly, and the two English-speaking traditions later settled on different vowels for the middle syllable.
A simple way to remember which is which: American English favours the plain a in pajamas, while British English keeps the y in pyjamas — the same letter that shows up in other British-leaning borrowings. Retailers shipping to both markets often list both spellings so shoppers can find the product either way.
