Lewis Short
affirmātĭo | adf- (noun F) : (), , affirmo
* An affirmation, declaration, confirmation, or averment of a fact or assertion: est enim jus jurandum adfirmatio religiosa,Cic. Off. 3, 29; so Planc. ap. Cic. Fam. 10, 21, and Cic. ib. 7: in spem venire alicujus adfirmatione de aliqua re,Caes. B. G. 7, 30: constantissima annalium adfirmatione,Plin. 28, 2, 4, § 15; multā abfirmatione abnuere,Curt. 6, 11.
Charlton T. Lewis, Charles Short, A Latin Dictionary