(Law) The transfer of possession of personal property from a debtor to a creditor as security for a debt or engagement; also, the contract created between the debtor and creditor by a thing being so delivered or deposited, forming a species of bailment; also, that which is so delivered or deposited; something put in pawn. Note: Pledge is ordinarily confined to personal property; the title or ownership does not pass by it; possession is essential to it. In all these points it differs from a mortgage (see Mortgage); and in the last, from the hypotheca of the Roman law. See Hypotheca.