1 a [count] : a drawing or picture that shows only the shape of an object — often followed by of
An outline of his face showed his high forehead, long nose, and small chin.
Outlines of animals were carved into the cave's walls.
1 b [noncount] : a style of drawing in which only the outer edges of an object are shown
The pictures were drawn in outline and then filled in with color.
2 [count] : a line that is drawn around the edges of something
The leaves etched into the vase have a gold outline.
3 : a written list or description of only the most important parts of an essay, speech, plan, etc. [count]
Organize your essay by writing an outline in which you state your main idea followed by your supporting points.
a plot outline
a brief outline of American history
Her speech was written in outline on note cards.
Learn about outline as a verb.