What does Bilal mean?
From the root b-l-l (ب-ل-ل, 'to moisten, to wet'), understood as 'moisture, wetting, freshness'. Famously borne by Bilal ibn Rabah, the Abyssinian companion of the Prophet and Islam's first muezzin.
What does Sultan mean?
From Arabic 'sultan', originally an abstract noun meaning 'strength, authority, rulership' (from 'sulta', power/authority), later a sovereign's title. Note: 'ruler/authority', and distinct from 'malik' (king) proper.