Gain means to get or obtain something, especially through effort or as a result of change. When you gain knowledge from reading, you acquire new information you didn't have before. When a runner gains speed during a race, she moves faster than she was moving earlier. When you gain someone's trust, you earn it through your actions over time.

The word often emphasizes increase or improvement. A plant gains height as it grows. A team gains confidence after winning several games in a row. Students gain skills through practice and study.

Gain can also be a noun describing what you've obtained. The phrase “no pain, no gain” means that worthwhile achievements usually require hard work or sacrifice. When investors talk about financial gains, they mean profits or increases in value.

The opposite of gain is lose. You might gain a friend or lose one, gain weight or lose it, gain ground in a competition or lose it. Understanding what you hope to gain from an activity helps you decide whether the effort is worthwhile.