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Agakamon is the language of higher beings, thought to be spoken by the Yods themselves.
Roughly translated, Agakamon means "Language of those who came from air," which is appropriate considering that when a higher being appears on Adelpha, they reportedly fall from the sky in Okaar following a bright flash of light.
As Cutter Slade discovered upon his arrival, it is eerily similar to the English language.
Agakamon is, in fact, the English language, brought to Adelpha by the science team.