Delnak
From The Stargate Omnipedia
Goa'uld term for "crystal," specifically for the variety used by the Goa'uld in the powering and control of their various technologies.
KEY EPISODE
Deadman Switch - While he and Carter are trapped in the back of Aris's cargo ship, Teal'c has to force himself to translate from Goa'uld to English under stress.