The term 'Female Big Cat' refers to two species of large cats, the lioness and the tigress. Both are female members of the cat family, and both are known for their strength and ferocity. The lioness is the female counterpart of the male lion, and the tigress is the female counterpart of the male tiger. Both animals are apex predators in their respective habitats, and they play an important role in maintaining the balance of their ecosystems.