Meaning

noun something clearly established

noun property that your creditor can claim in case you default on your obligation

noun a prisoner who is held by one party to insure that another party will meet specified terms

originFrom Middle English surete, attested since the early 1300s in the sense "guarantee, promise, pledge, assurance", from Anglo-Norman seurté/Old French seurté with the same meaning (whence modern French sûreté), from Latin sēcūritās. Equivalent to sure + -ty. The senses "security, safety, stability" and "certainty" are attested since the late 1300s. "One who undertakes to pay if another does not" is…

Etymology from Wiktionary, CC BY-SA 3.0