Meaning and elaboration
Meaning: The Source of Brahma's Creative Power and therefore of all creation.
Elaboration
The name Brahma Yonih means "the Womb (Yoni) of Brahma" or "the Source (Yoni) of Brahma." It points to Kali as the primordial ground from which even the creative principle itself arises.
The 'Yoni' as the Primordial Source In Hindu cosmology, the Yoni is the sacred symbol of divine feminine creative energy, the universal womb from which all existence comes forth. It is the generative principle, the unmanifest potential that gives rise to all forms. As Brahma Yonih, Kali is not simply another creator within the cosmos. She is the very source from which the creator god Brahma receives the power to create.
Transcending the Creator Although Brahma is honored as the creator of the universe, this name places Kali before him and above him. His power to manifest the cosmos is an emanation of her Shakti. She is the ground of his being, the fundamental force that makes his cosmic function possible. In this way, she is revealed as the ultimate source and substance of all existence.
The Ultimate Reality This aspect of Kali points to her status as Para Brahman, the Supreme and Transcendent Reality. She is the undivided unity from which all dualities, including creator and created, emerge. As Brahma Yonih, she is the eternal and unchanging source behind all change, the boundless ground in which creation unfolds. For the devotee, to meditate on Kali as Brahma Yonih is to seek the very origin of all creation, going beyond every intermediary and recognizing her as the unmanifest source of all that is manifested.