margin

The edge of the paper, typically left blank when printing but sometimes used for annotations etc.

The edge or border of any flat surface.

The edge defining inclusion in or exclusion from a set or group.

A difference or ratio between results, characteristics, scores.

A permissible difference; allowing some freedom to move within limits.

The yield or profit; the selling price minus the cost of production.

Collateral security deposited with a broker, to compensate the broker in the event of loss in the speculative buying and selling of stocks, commodities, etc.

To add a margin to.

To enter (notes etc.) into the margin.