Denarius picturing Quirinus on the obverse, and Ceres enthroned on the reverse, a commemoration by a moneyer in 56 BCE of a Cerialia presented by an earlier Gaius Memmius as aedile[1]
https://en.wikipedia.org/wiki/Quirinus
cereal |ˈsirēəl|
noun
a grain used for food, such as wheat, oats, or corn.
• (usually cereals) a grass producing a cereal grain, grown as an agricultural crop: [as modifier] : low yields for cereal crops.
• a breakfast food made from roasted grain, typically eaten with milk: a bowl of cereal | [as modifier] : a cereal box.
ORIGIN
early 19th century (as an adjective): from Latin cerealis, from Ceres, the name of the Roman goddess of agriculture.