A binding, pledging, or coming together. A mutual pact, contract, or agreement.
An engagement to marry is a BILATERAL CONTRACT between two people whereby they mutually promise to marry one another. Formerly, a breach of the engagement to marry was a CAUSE OF ACTION in several jurisdictions, but this is not true today.
An engagement letter is a clear delineation of an agreement that covers a particular project or employment. An attorney can require a client to sign such a letter to indicate that the person has been employed to perform specifically designated tasks.