twin-size

or twin-sized

[ twin-sahyz ]

adjective

1. (of a bed) approximately 39 inches (99 centimeters) wide and between 75 and 76 inches (191 and 193 centimeters) long; single.
2. pertaining to or made for a twin-size bed:

   twin-size sheets.

Word History and Origins

Origin of twin-size¹

First recorded in 1925–30

Example Sentences

The mother carries what looks like a twin-size cotton futon mattress.

From The Daily Beast