The word asylum has origins dating back to ancient Greece, seizing merchant ships to cover losses, and protecting accidental murders.
Though today the term has a few common meanings that are used liberally in various contexts, in immigration law, asylum is rather specific. Interestingly, the legal sense of the term that we know of today may have actually come into existence before the Grecians invented the word.
Asylum for Accidental Murderers
Curiously, the practice of asylum is posited to come from the ancient Israelites. Then, apparently, after a person accidentally killed another person, to avoid being murdered out of revenge by that person's family or clan, there were "divinely-designated" places of refuge where the person could not be killed.
What About the Word Itself?
The term asylum comes from the Ancient Greek "asylos." That term derives from "a-" meaning "without," and "sylon" or "syle" meaning "right of seizure." The word later developed in Greek to "asylos" to mean "refuge or fenced territory," and "asylon" to mean "inviolable, safe from violence."
The term came to English around the 15th century as "asyle" and took on the Latin meaning of "sanctuary," which somewhat combines both ancient Greek meanings, similarly to how we know it today. Interestingly, before the term came to be applied to those seeking asylum from political or religious persecution, it was commonly applied to criminals seeking protection from prosecution.
What About the Merchant Ships?
Even more curiously, part of the ancient Greek term that formed asylum, "sylon," also used to refer to "stripping the armor off a slain enemy," and was later extended to "the right of seizing the ship or cargo of a foreign merchant to cover losses received through him."