Definition of "Margin" :

noun: a permissible difference; allowing some freedom to move within limits

noun: an amount beyond the minimum necessary

"The margin of victory."

noun: the blank space that surrounds the text on a page

"He jotted a note in the margin."

noun: (finance) the net sales minus the cost of goods and services sold

noun: the amount of collateral a customer deposits with a broker when borrowing from the broker to buy securities

noun: the boundary line or the area immediately inside the boundary