What term best describes the power to provide forgiveness for federal crimes?

The term that best describes the power to provide forgiveness for federal crimes is "pardon." A pardon is an official decision by a government to allow a person to be relieved from the legal consequences of a crime, effectively absolving them of guilt and restoring their civil rights. This power is typically granted by the president in the United States.

In contrast, a reprieve refers to a temporary delay in the punishment of a crime, rather than forgiveness itself. Amnesty generally involves a blanket pardon for a group of individuals, often in cases of political offenses, but is broader than simply forgiving a crime. Executive privilege, on the other hand, pertains to the president's ability to withhold information from other branches of government or the public, which is unrelated to the notions of forgiveness for crimes. Therefore, "pardon" is the most accurate term in this context.