Ann: Secondary Trading Prospectus , page-12

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An escrow is:

an arrangement where an independent trusted third-party receives and disburses money and/or documents for two or more transacting parties, with the timing of such disbursement by the third-party dependent on the performance by the parties of agreed-upon contractual provisions, or
an account established by a broker, under the provisions of license law, for the purpose of holding funds on behalf of the broker's principal or some other person until the consummation or termination of a transaction;[1] or,
a trust account held in the borrower's name to pay obligations such as property taxes and insurance premiums.
The word derives from the Old French word escroue, meaning a scrap of paper or a roll of parchment; this indicated the deed that a third party held until a transaction was completed.[2]