The cleaner methods for functional colouration of textiles are in huge demand. The use of toxic metallic mordants for achieving such an objective makes the entire process unsustainable. The biomolecules present in various green extracts can be utilized for achieving functional colouration. Kigelia Africana (KA) and Terminalia chebula (TC) are known as a rich source of biomolecules possessing antioxidant and antibacterial activities. In the present work, a bio-mordant Terminalia chebula was utilized as a mordant for natural dyeing of wool using Kigelia Africana natural dye. The colouration and functional properties were assessed using standard methods. The dyed wool fabric with satisfactory colour values and fastness properties was obtained. The dyed wool displayed antioxidant activity up to 99.41%, antibacterial activity up to 97.8% and excellent UPF. The novel sustainable option for functional colouration of wool was thus explored.