What is the meaning of Two-spirit?

Involving two spirits; especially, pertaining to the doctrine of dualism espoused in the so-called Treatise on the Two Spirits in the Dead Sea Scrolls.

A Native North American bisexual, homosexual, or gender-variant person; especially one belonging to a traditional tribal third-gender, fourth-gender, or transgender cultural category that has a ceremonial role.

Of, pertaining to, or being a two-spirit (noun sense).

Source: wiktionary.org