› [I or T] to write your name, usually on a written or printed document, for example to show that you agree with its contents or have written or created it yourself: sign a contract/agreement/declaration We've already agreed the details and I just need to sign a contract. sign a letter/form/cheque Please sign your name below if you are available to help. Sign here please.
signed and sealed (also signed, sealed, and delivered) › finished and official because all the necessary documents have been signed: The project can start now that the contract has been signed and sealed.
sign on the dotted line › to agree to do something, especially by signing an agreement: Many people sign on the dotted line without reading their policy documents.