• Etymology Today from M-W: cordial \KOR-jul\
1 : tending to revive, cheer, or invigorate
2 a : sincerely or deeply felt *b : warmly and genially affable

"Cordial" has the same Latin root ("cor") as "concord" (meaning "harmony") and "discord" (meaning "conflict"). "Cor" means "heart," and each of these "cor" descendants has something to do with the heart, at least figuratively. "Concord," which comes from "con-" (meaning "together" or "with") plus "cor," suggests that one heart is with another. "Discord" combines the prefix "dis-" (meaning "apart") with "cor," and it implies that hearts are apart. And anything that is "cordial," be it a welcome, a hello, or an agreement, comes from the heart.

• E.T. bonus, also from M-W: origins of riot act, as in: "She read her the riot act."
Many people were displeased when George I became king of England in 1714, and his opponents were soon leading rebellions and protests against him. The British government, anxious to stop the protests, passed a law called the "Riot Act" which allowed public officials to break up gatherings of 12 or more people just by reading aloud a certain message. That message warned those who heard it that they could be arrested and imprisoned for years if they didn't immediately separate and go home. By 1819, "riot act" was also being used more generally for any stern warning or reprimand.

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