the.com/easement

means A legal right to use another person's land for a specific purpose — like crossing it, running a pipe through it, or sharing a driveway — without owning it.

from From Old French aisement, meaning convenience, comfort, or 'that which gives ease,' rooted in aise (ease, comfort — the same ancestor that gives us the word 'ease' itself). The legal sense grew naturally from the general one: an easement is quite literally a convenience granted over someone else's property, formalized by English common law into the property right it names today.