A sketch is a drawing that is done quickly without a lot of details. Artists often use sketches as a preparation for a more detailed painting or drawing.

If you sketch something, you make a quick, rough drawing of it.

A sketch of a situation, person, or incident is a brief description of it without many details.

If you sketch a situation or incident, you give a short description of it, including only the most important facts.

A sketch is a short humorous piece of acting, usually forming part of a comedy show.