Where does “Seleucides” come from?

Seleucides (Latin) comes from Ancient Greek Σελευκίδης, from Ancient Greek Σέλευκος, from Ancient Greek ζάλευκος — very white.

Ancestry of “Seleucides”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	Σελευκίδης	—
2	Ancient Greek	Σέλευκος	Seleucus; Seleucos
3	Ancient Greek	ζάλευκος	very white