1 To confirm a legal decision, particularly (of an appeal court) to confirm a judgment made in a lower court.
2 To promise in solemn form to tell the truth while giving evidence or when making an affidavit. Under the Oaths Act 1978, any person who objects to being sworn on oath, or in respect of whom it is not reasonably practicable to administer an oath, may instead affirm. Affirmation has the same legal effects as the taking of an oath.
3 To treat a contract as continuing in existence, instead of exercising a right to rescind it for misrepresentation or other cause (see voidable contract) or to treat it as discharged by reason of repudiation or breach (see breach of contract). Affirmation is effective only if it takes place with full knowledge of the facts. It may take the form of an express declaration of intention to proceed with the contract; alternatively, that intention may be inferred from conduct (if, for example, the party attempts to sell goods that have been delivered under a contract voidable for misrepresentation). Lapse of time without seeking a remedy may be treated as evidence of affirmation (Clough v London and North Western Railway Co (1871) LR 7 Exch 26).