This has two meanings:
(1) American Depositary Receipts (also American DepositOry (DepositAry) Rights), mechanism for trading shares in non-U.S. companies on U.S. exchanges. Shares in the foreign company are placed in trust with a U.S. bank (the depository/depositary), which issues receipts entitling the holder to a specified number of the shares per Receipt. The Receipts or ADRs are then traded on the U.S. exchanges.
(2) Alternative dispute resolution, i.e., methods of resolving legal disputes that avoid a courtroom trial, for example mediation, arbitration, adjudication or conciliation.