in Logic, the asserting the truth of any proposition.

in Law, denotes an indulgence allowed to the people called Quakers; who, in cases where an oath is required from others, may make a solemn affirmation that what they say is true; and if they make a false affirmation, they are subject to the penalties of perjury. But this relates only to oaths taken to the government, and on civil occasions; for Quakers are not permitted to give their testimony in any criminal case, &c.

AFFIRMATION is also used for the ratifying or confirming the sentence or decree of some inferior court: Thus we say, the house of lords affirmed the decree of the chancellor, or the decree of the lords of session.