Affirmative
A Dictionary of Law · Henry Campbell Black · 1891
A Dictionary of Law
That which declares positively; that which avers a factto be true; that which establishes; the opposite of negative. The party who, upon the allegations of pleadings joining issue, is under the obligation of making proof, in the first instance, of matters alleged, is said to hold the affirmative, or, in other words, to sustain the burden of proof.
Abbott.