A proffer in court can refer to different things depending on the context in which it is used. Here are the different meanings of proffer in court:

• Offer of proof: In the context of a trial or a hearing, a proffer means an offer of proof. It is a formal way for an attorney to tell the court what evidence would have been presented if it had been allowed.

• Informal offer of information: In the context of pretrial negotiations, a proffer refers to an informal offer of information by an individual, usually a target, but sometimes a witness or subject, to one or more law enforcement officials. This is also called "queen for a day".

• Meeting between a defendant or suspect and the government: A proffer is a meeting between a criminal defendant or suspect and the government that usually takes place at the local U.S. Attorneys Office rather than in court. At the proffer, a defendant is represented by counsel and the government is represented by the prosecutor along with the investigating agents. The defendant is expected to share with the government everything they know about the crime in question and the people involved during a proffer. The defendant is legally required to tell the truth and not withhold any relevant information. A proffer is unique in that the defendant essentially incriminates themselves by openly talking about both their role in and their knowledge of the crime committed. The purpose of a proffer is to encourage defendants to cooperate with the government and provide information that can be used against others involved in the crime. In exchange for the information, the government may offer the defendant immunity or a favorable plea deal regarding sentencing. However, a proffer agreement is not a promise of absolute immunity but an agreement between the defendant and the government.

It is important to note that a proffer agreement is a written contract between a federal prosecutor and a defendant, or a person under criminal investigation, where the defendant agrees to provide the prosecutor with useful information. The statements they made will not be used against them in future criminal proceedings. Typically, proffer statements are made with the understanding that the prosecutor will either grant them immunity from federal criminal prosecution or offer a favorable plea deal regarding sentencing. Additionally, their proffer statements are expected not to be used against them later. Proffer agreements often require significant negotiation, so it is important that you consult a criminal lawyer before agreeing to enter into a proffer agreement to protect your legal rights.