The term 'Feminine Side' is often used to refer to the female gender, and is represented by the crossword solution 'Yin', which is a three-letter word. Yin is an ancient Chinese concept that represents the feminine, passive, dark, and negative aspects of life. It is often seen as the opposite of Yang, which is the masculine, active, light, and positive aspects of life. Together, Yin and Yang represent the balance of the universe.