agreement

In medieval French, a gré meant something like “to one’s liking,” which is why agree still carries a faint whiff of pleasure, not just logic. The leap from “I like this” to “we have a contract” is wonderfully human: first comes goodwill, then paperwork, then somebody shoves a seal into hot wax. That little noun-making ending -ment is the same family gear that gives us arrangement and movement, turning actions into solid things you can point at. Meanwhile, agree shares a distant ancestral glow with words like grateful and gratitude, because all of them circle back to the idea of being welcomed. By the early 15th century, English was already using agreement for both harmony of opinion and formal settlement, which is basically the whole story of civilization in one tidy word.