affirmative

Concise Oxford English Dictionary © 2008 Oxford University Press:
affirmative/əˈfɜːmətɪv/

▶adjective

• 1 agreeing with or consenting to a statement or request.

  ■ Grammar & Logic stating that a fact is so.

  Contrasted with negative and interrogative.

• 2 denoting proposed legislation which must receive an affirmative parliamentary vote before it can come into force.

▶noun an affirmative statement or word.

■ Logic a statement asserting that something is true of the subject of a proposition.

▶exclamation chiefly N. Amer. yes.

– phrases
in the affirmative so as to accept or agree to a statement or request.

– derivatives
affirmatively adverb.

– origin ME (in the sense ‘assertive, positive’): via OFr. from late L. affirmativus, from affirmare (see affirm).