French window 
noun (usually French windows)
Each of a pair of glazed doors in an outside wall, serving as a window and door, typically opening on to a garden or balcony: Julia walked out through the open French windows on to the terrace...
- Patio doors and French windows should be fitted with a special lock at the top and bottom
- Ground floor or garden apartments have French windows leading out to their own patio areas.
- Architects have come up with ideas for an urban square surrounded by new housing, creating back gardens and putting French windows into existing terraced homes, and giving some homes in New Market Street front gardens.