To indicate by lines drawn in the form or figure of; to represent by sketch, design, or diagram; to sketch out; to portray; to picture; in drawing and engraving, to represent in lines, as with the pen, pencil, or graver; hence, to represent with accuracy and minuteness
If you delineate something such as an idea or situation, you describe it or define it, often in a lot of detail. Biography must to some extent delineate characters