Inner describes what's on the inside, toward the center, or hidden from view. An inner pocket sits deep inside your jacket where your hand has to reach past the outer pockets to find it. The inner workings of a clock are the gears and springs tucked away behind the clock face, doing the real work while staying invisible.

The word often contrasts with outer. If you're standing in an inner circle of students, you're closer to the center than those in the outer circle. An inner tube sits inside a bicycle tire, protected by the rubber on the outside. When astronauts describe Earth's structure, they talk about the inner core, a ball of solid metal at the planet's center, thousands of miles beneath our feet.

Inner also describes private thoughts and feelings. Your inner life includes all the ideas, worries, and dreams you think about but don't necessarily share. When someone shows their inner strength, they reveal courage or determination that wasn't obvious before. Your inner voice is that silent conversation you have with yourself when making decisions or working through problems, the thoughts only you can hear.