Southernmost means located farthest to the south compared to all other things in a group. If you're looking at a map of the United States, Key West, Florida is one of the southernmost cities you can drive to, sitting near the bottom tip of the country.

The word works like a superlative: just as “tallest” means the most tall, “southernmost” means the most south. Antarctica is Earth's southernmost continent. In a row of houses on your street, one house will be the southernmost. When explorers raced to reach the South Pole in the early 1900s, they were trying to reach the southernmost point on the planet.

You'll also see related words like northernmost (farthest north), easternmost (farthest east), and westernmost (farthest west). These directional superlatives help us describe locations precisely. The southernmost classroom in your school might be the one that gets the most afternoon sunlight, while the southernmost penguin colonies in Antarctica endure the coldest, harshest conditions on Earth.