The Vietnamese word "tàn nhang" is a noun that refers to "freckles." Freckles are small, light brown spots that can appear on the skin, often due to sun exposure. They are most commonly found on the face, arms, and shoulders.
In summary, "tàn nhang" is a specific term used to describe freckles on the skin. It is commonly used in discussions about beauty, skincare, and personal appearance.