Single means one, alone, or individual rather than multiple or paired. When you pick a single apple from a tree, you're choosing just one. A single bed is designed for one person, unlike a double bed meant for two.

In everyday use, single emphasizes that something stands alone. A single mistake might ruin an entire batch of cookies. A runner might win a race by a single second. When something happens without a single exception, it means there are no exceptions at all.

The word also describes someone who isn't married or in a romantic relationship. An unmarried adult is single, as opposed to married, engaged, or partnered.

In baseball, a single is a hit that lets the batter safely reach first base. It's the most common type of hit, and while it's not as exciting as a home run, singles are how teams gradually advance runners and score runs. A team that strings together several singles can be just as successful as one that relies on home runs.

Single can also mean particularly focused or determined, as in single-minded, when someone pursues a goal with complete dedication, ignoring distractions and focusing all their energy on what they want to achieve.