From Halopedia, the Halo wiki
Xankara is a state of meditative existence experienced by a Forerunner while in self-imposed exile within a Cryptum. An individual in xankara remained in deep suspended animation, with their consciousness completely immersed in the Domain in a timeless, transcendent state. Xankara was not permanent and a Forerunner would regain a normal state of awareness when revived from the Cryptum.
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