creditor

From Middle English creditour, borrowed via Anglo-Norman creditour from Latin crēditor. That Latin word traces to crēditum, meaning "loan," itself from crēditus, the past participle of crēdō, "to lend."

The word has stayed close to its root sense throughout — someone to whom money or trust is owed, carried forward from Latin through Anglo-Norman into Middle English with little change in meaning.

It shares its root, Latin crēdō ("to lend" or "to believe"), with any English word built on the idea of belief or trust, though the facts here don't name a specific sibling word.