Translations
According to Wasilewska et al., du-ku translates as "holy hill", "holy mound" [...E-dul-kug... (House which is the holy mound)], or "great mountain"
Divine
The location is otherwise alluded to in sacred texts as a specifically identified place of godly judgement.
The hill was the location for ritual offerings to Sumerian god(s). Nungal and the Anunna dwell upon the holy hill in a text written from Gilgamesh.
References
Du-Ku Wikipedia(Text) CC BY-SA