Pajamas are the soft, loose clothes you sleep in — a top and a pair of trousers, cotton, a size too big. Christmas morning spent in your pajamas, a child carried out to the car in pajamas and a coat.
Like trousers and scissors, pajamas is always plural: a pair of pajamas, these pajamas, and never a pajama. Americans write pajamas, the British write pyjamas, and the short form pjs works in both. In front of another noun the word goes singular — pajama top, pajama bottoms, pajama party. The cat's pajamas is old American slang for something wonderful, and it still gets an outing when somebody is being deliberately quaint.
1nounpajamasA loose top and trousers worn in bed. Always plural.
“He came downstairs in his pajamas and bare feet.”
synonyms: nightclothes
pajamas is clothing.
Also accepted in games: pyjamas, pjs
English took pajamas from Hindi pajama and Urdu, which had it from Classical Persian pajama, meaning trousers or drawers. The Persian word is two pieces: pa, leg, and jama, garment. Half the sleeping world is dressed, by name, in a pair of Persian leg-garments.
fa-cls
پَاجَامَه — trousers, drawers
Urdu
پاجامہ
Hindi
पाजामा
English, today
pajamas
Built from
inc-hnd - (Hindi पाजामा / Urdu پاجامہ), from fa-cls پَاجَامَه (“trousers, drawers”), from پَا (“leg”) + جَامَه (“garment”).
Etymology from Wiktionary, CC BY-SA