The C. Luwian word da-ak-ku-u-i-iš
Word da-ak-ku-u-i-iš
IPA dakkuiš
Meaning dark
See also Hittite: da-an-ku-iš ‘black, dark’

Other words that might be of interest
ti-wa-az ‘sun god’, pa-a-ḫu-u-ur ‘fire’