n.pl. (US pajamas)
1. a suit of loose trousers and jacket for sleeping in.
2 loose trousers tied round the waist, worn by both sexes in some Asian countries.
3 (pyjama) (attrib.) designating parts of a suit of pyjamas (pyjama jacket; pyjama trousers).
Etymology: Urdu pa(e)jama f. Pers. pae, pay leg + Hindi jama clothing