To coin a word or phrase means to invent it and introduce it into the language. When Benjamin Franklin coined the term “battery” for his electrical experiments, he created a new word that stuck. When Lewis Carroll coined “chortle” in his poem “Jabberwocky,” he blended “chuckle” and “snort” into something fresh that people loved and started using. Scientists, writers, and everyday people coin new words when existing language doesn't quite capture what they need to express.

A coin is also a small, flat piece of metal used as money. Coins have been around for thousands of years, stamped with images and words to show their value. The ancient Greeks made some of the first coins around 600 BCE, revolutionizing trade because coins were easier to carry and count than hauling around livestock or sacks of grain. Today's coins, made mostly from cheaper metals like zinc and copper, are mainly useful for small purchases, though many modern transactions happen without physical money at all.