A window or an opening in a wall for light and air.

Origin: The word 'खिड़की' (khidki) originates from the Hindi language, with its roots tracing back to the Sanskrit word 'खिद्र' (khidra), meaning 'small opening'. This word was adopted into Hindi with phonetic simplifications, evolving into its current form.
Historical and Cultural Context: The concept of a window is ancient, with early references in Vedic texts where small openings were used in structures to allow light and air. In traditional Indian architecture, 'खिड़की' was a crucial element in homes, not only for ventilation but also for observing the outside world while maintaining privacy.
Evolution: Over time, 'खिड़की' has been borrowed into various regional languages of India, often with slight phonetic modifications. In Marathi, it becomes 'खिडकी', and in Bengali, 'খিড়কি'. Despite these variations, the word maintains a similar meaning across these languages.
Modern Relevance: Today, 'खिड़की' is widely used in Hindi-speaking regions to refer to both traditional and modern windows. It appears in idiomatic expressions, such as 'खिड़की से देखना' (to look through the window), symbolizing curiosity or observation.

In traditional Indian homes, 'खिड़की' often served dual purposes: providing ventilation and acting as a secret vantage point from which residents could observe street activities without being seen.