In the context you mention, an outline is similar to drawing a rough picture of something, or as Susan said, a list of topics for a report. It gives an approximate idea, or a rough verbal picture of the situation, without going into details.

Sorry, I should have elaborated on what context. I mean outline as a verb and in accordance with this: "Labour unconvinced by 2014/15 surplus outline."

Outline can be a noun or a verb. As a noun, it can mean the outer lines of a shape, for example when you make a dress you cut along the outline of the pattern. An outline can also be a way to organize notes for research, a list of topics and subtopics and details you make in preparation for writing a report. As a verb, it can mean to trace the outer lines of an object, or it can mean to create an outline. http://www.ldoceonline.com/dictionary/outline_1

Sorry - your question is quite ambiguous. In what context?