Definition: having the green color of a leek
The Latin word for “leek,” prason, gave us several words in English. Prasine itself was once used as a noun to designate the green precious stone and the color that we still call “emerald,” but those meanings are now obsolete. Porraceous means “having the light green color of leek leaves.” Both chrysoprase and prase mean a green kind of quartz stone known as chalcedony used as a gem, and chrysoprase also means “a brilliant to light green.”
Although the wearing of the green is an Irish tradition, we should also point out that leeks are a traditional Welsh national symbol.