A sketch is a quick, rough drawing that captures the basic idea or outline of something without all the details. When an artist sketches a person's face, she might draw just the shape of the head, the position of the eyes and nose, and a few lines for shading, completing it in minutes rather than hours. Architects sketch building designs on napkins during lunch meetings. Scientists sketch diagrams to explain their theories.

Sketches work because they focus on what matters most. A nature artist might sketch twenty different birds in an afternoon, capturing each one's distinctive shape and posture without worrying about every feather. These quick studies help her understand her subjects better than one careful, detailed painting would.

The word also describes a short, funny performance. Comedy shows often include sketches, brief scenes that tell a complete joke or story in just a few minutes. A group of students might write and perform sketches for a talent show, each one presenting a humorous situation with a beginning, middle, and end.

When you sketch out an idea, you're outlining the main points without filling in every detail, like sketching out a plan for your summer or sketching out the plot of a story you want to write.