See also: Sister-in-law in Hindi, English-Tamil translation What does sister-in-law mean in Tamil, Tamil sister-in-law translation, definition of sister-in-law, pronunciation and examples of sister-in-law in Tamil. See sister-in-law meaning in Tamil, definition of sister-in-law, translation and meaning of sister-in-law in Tamil. Learn and practice sister-in-law pronunciation. Find the answer to what sister-in-law means in Tamil. A brother-in-law or sister-in-law is the spouse of a brother or sister or a brother or sister of the spouse or the person married to the spouse`s brother or sister.