positive

Concise Oxford English Dictionary © 2008 Oxford University Press:
positive/ˈpɒzətɪv/

▶adjective

• 1 consisting in or characterized by the presence rather than the absence of something.

  ■ expressing or implying affirmation, agreement, or permission.

  ■ [often in combination] having a specified substance or condition: HIV-positive.

• 2 constructive, optimistic, or confident.

• 3 with no possibility of doubt; certain.

• 4 (of a quantity) greater than zero.

• 5 containing, producing, or denoting the kind of electric charge opposite to that carried by electrons.

• 6 (of a photographic image) showing light and shade or colours true to the original.

• 7 Grammar (of an adjective or adverb) expressing a quality in its basic, primary degree. Contrasted with comparative and superlative.

• 8 chiefly Philosophy dealing only with matters of fact and experience. See also positivism (sense 1).

▶noun

• 1 a desirable quality or attribute.

• 2 a positive photographic image, especially one printed from a negative.

– derivatives
positiveness noun,
positivity noun.

– origin ME (orig. referring to laws as being formally ‘laid down’): from OFr. positif, -ive or L. positivus, from posit-, ponere ‘place’.