To outline or mark out.
To describe or depict with words or gestures.
To depict, represent with pictures.
To sketch out, draw or trace an outline.
To open (anything covered or closed); to lay open to view or contemplation; to bring out in all the details, or by successive development.
To undo a folding.
To release from a fold or pen.
To turn out; to happen; to develop.
To reveal.
In functional programming, a kind of higher-order function that is the opposite of a fold.