sketch

A rapidly executed freehand drawing that is not intended as a finished work, often consisting of a multitude of overlapping lines.

A rough design, plan, or draft, as a rough draft of a book.

A brief description of a person or account of an incident; a general presentation or outline.

A brief musical composition or theme, especially for the piano.

A brief, light, or informal literary composition, such as an essay or short story.

(informal) An amusing person.

(slang, Ireland) A lookout; vigilant watch for something.

(UK) A humorous newspaper article summarizing political events, making heavy use of metaphor, paraphrase and caricature.

(category theory) A formal specification of a mathematical structure or a data type described in terms of a graph and diagrams (and cones (and cocones)) on it. It can be implemented by means of “models”, which are functors which are graph homomorphisms from the formal specification to categories such that the diagrams become commutative, the cones become limiting (i.e., products), the cocones become colimiting (i.e., sums).