a pair of casement windows extending to the floor and serving as portals, especially from a room to an outside porch or terrace.
Origin of French window
First recorded in 1795–1805
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
(sometimes singular) British a pair of casement windows extending to floor level and opening onto a balcony, garden, etcUS and Canadian name: French doors
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