"Pyjama" redirects here. For other meanings of "pyjama" or "pajama" or similar see Pajamas (disambiguation).Pajamas American English, spelled pyjamas British English, often shortened to PJs, jimmies, jimjams or jammies, can refer to several related types of clothing. Pajamas are loose-fitting, two-piece garments derived from the original garment and worn chiefly for sleeping, but sometimes also for lounging, also by both genders.