This word came into English from Urdu, although its roots are in the
Persian pāy 'leg' + jāma 'clothing'.
Its earliest uses in English refer to loose draw-string trousers made of
cotton or silk, worn in some Middle Eastern and Asian countries. The word first appeared in English in the
early 19th century in a range of spelling forms, including such exotics as paunjammahs, paejamus, paijamahs, peijammahs, pigammahs; later in the 19th century the modern forms pyjamas and pajamas began to appear, along with pyjammas, which is still common today. The -s was added to the word by comparison
with words like trousers and drawers; the singular forms pajama and pyjama are sometimes found, especially in compounds like pyjama-party, or pyjama-top. Other examples
recorded in the early 20th century include pie-jim-jams
- which survives today as jim-jams -
and a shortened form: pyjams, used by
John Betjeman in Summoned by Bells
(1960). Today pyjamas is the standard spelling in UK English and pajamas is the standard US
spelling.
