term:

Margin

margin n

1 : the difference between net sales and the cost of the merchandise sold from which expenses are usually met or profits derived
2 : the amount by which the market value of collateral is greater than the face value of a loan
3 a : cash or collateral deposited in a regulated amount by a client with a broker who is financing the purchase of securities see also regulation t
b : a deposit made with a broker by a client who is trading in futures

Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.