Where does “heliacus” come from?

heliacus (Latin) comes from Ancient Greek ἡλιακός, from Ancient Greek -ᾰκός — of or pertaining to, in the manner of; -ac.

Ancestry of “heliacus”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	ἡλιακός	of the sun
2	Ancient Greek	-ᾰκός	of or pertaining to, in the manner of; -ac