a recreation room.
Origin of rec room
First recorded in 1960–65; by shortening
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
US and Canadian a room in a house used by the family for relaxation and entertainmentIn full: recreation room
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012