a border; edge; brink; verge; as, the margin of a river or lake.-specifically: the part of a page at the edge left uncovered in writing or printing.-the difference between the cost and the selling price of an article.-something allowed, or reserved, for that which can not be foreseen or known with certainty.-collateral security deposited with a broker to secure him from loss on contracts entered into by him on behalf of his principial, as in the speculative buying and selling of stocks, wheat, etc.-to furnish with a margin.-to enter in the margin of a page.