Meaning and elaboration
Meaning: The Complete One, containing all perfection and plenitude.
Elaboration
Purna means "complete," "full," "perfect," or "whole." Applied to Mahakali, it reveals her as the absolute fullness of existence, untouched by lack, division, or imperfection.
The Absolute Totality As Purna, Kali is absolute and unbounded reality itself. She is not one aspect of divinity among many, but the totality of all that exists and all that can ever exist. In this sense, she is Parabrahmarūpiṇī, the form of the Ultimate Reality, the non-dual Brahman and the all-pervading consciousness.
Plenitude and Abundance Her completeness is infinite plenitude. She is the source of all abundance, knowledge, power, and being. All creation arises from her inexhaustible fullness, yet her essence remains undiminished. This echoes the ancient Vedantic declaration "Pūrna madah pūrṇa midam..." (That is whole, this is whole...), which affirms that the divine essence remains complete in all its manifestations.
Perfection and Wholeness Purna Kali embodies perfect wholeness. No aspect of existence falls outside her scope; no quality, attribute, or potential lies beyond her. For the devotee, this wholeness is also a spiritual realization: by merging individual consciousness into her ultimate reality, one comes to experience one's own inherent completeness.
Dispeller of Deficiency By meditating on Kali as Purna, the devotee moves beyond feelings of lack, incompleteness, and inadequacy, and begins to realize an intrinsic connection to the limitless and perfect nature of the Goddess. She fills every void, cosmic and individual alike, bringing a deep sense of spiritual fulfillment and freedom from the illusion of separation.