Alternate spellings: kelipot, kellipot, klippot, klippoth, qlipoth, qlippoth, and qlifot.
In both Western and Jewish systems of Kabbalah, the ten opposite, or averse, states of being/aspects of evil/unholy emanations depicted as spheres on the Tree of Death, the other side of the Tree of Life. Plural of qlippah, often translated as husk, peel, or shell, but can also be contemporarily thought of as a shadow. Other synonyms include envelope and cortex. Innate spiritual obstacles to holiness, they are also seen as a means of self-examination and spiritual growth by confronting and transcending these states and aspects.
The ten qliphoth/alternative name/alternative name, (cortex if any), and the sephira of the Tree of Life they oppose are:
Bonus: Belial is in opposition to Da'ath.