pajamas

This term refers to a set of clothing designed for sleep or lounging. In American English, the spelling is pajamas, while British English typically uses pyjamas. The word is almost exclusively used in the plural form because the garment consists of two separate pieces, a top and a bottom.

Because it is a plurale tantum, it takes a plural verb (e.g., "my pajamas are dirty") rather than a singular one. To refer to a single set, the partitive phrase "a pair of" is used, as in "a pair of silk pajamas."