To undo or open something that is fastened, such as a button on clothing.

बटन खोलना

English Usage: She decided to unbutton her blouse to feel more comfortable.

Hindi Usage: उसने अपने ब्लाउज का बटन खोलने का निर्णय लिया ताकि वह अधिक आरामदायक महसूस कर सके।