positive

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Characterized by or displaying certainty, acceptance, or affirmation.
• adjective Measured or moving forward or in a direction of increase or progress.
• adjective Desirable, admirable, or beneficial.
• adjective Optimistic or constructive.
• adjective Not disparaging or malicious.
• adjective Very confident; certain: synonym: sure.
• adjective Explicitly or openly expressed or laid down.
• adjective Admitting of no doubt; irrefutable.
• adjective Concerned with practical rather than theoretical matters.
• adjective Of or relating to positivism.
• adjective Of or relating to positive law.
• adjective Of or relating to religion based on revelation rather than on nature or reason alone.
• adjective Informal Utter; absolute.
• adjective Relating to or designating a quantity greater than zero.
• adjective Relating to or designating the sign (+).
• adjective Relating to or designating a quantity, number, angle, or direction opposite to another designated as negative.
• adjective Relating to or designating an electric charge of a sign opposite to that of an electron.
• adjective Of or relating to a body having fewer electrons than protons.
• adjective Chemistry Of or relating to an ion, the cation, that is attracted to a negative electrode.
• adjective Medicine Indicating the presence of a particular disease, condition, or organism.
• adjective Biology Indicating or characterized by response or motion toward the source of a stimulus, such as light.
• adjective Having the areas of light and dark in their original and normal relationship, as in a photographic print made from a negative.
• adjective Grammar Of, relating to, or being the simple uncompared degree of an adjective or adverb, as opposed to either the comparative or superlative.
• adjective Driven by or generating power directly through intermediate machine parts having little or no play.
• noun An affirmative element or characteristic.
• noun Mathematics A quantity greater than zero.
• noun Physics A positive electric charge.
• noun A photographic image in which the lights and darks appear as they do in nature.
• noun The uncompared degree of an adjective or adverb.
• noun A word in this degree.
• noun Music A division of some pipe organs, similar in sound to the great but smaller and less powerful.

from The Century Dictionary.

• Specifically, noting an oiling or lubricating device in which the oil is made to flow by pressure, due either to gravity or to pumping.
• Laid down as a proposition; affirmed; stated; express: as, a positive declaration.
• Of an affirmative nature; possessing definite characters of its own; of a kind to excite sensation or be otherwise directly experienced; not negative. Thus, light is positive, darkness negative; man is positive, nonman negative.
• Arbitrarily laid down; determined by declaration, enactment, or convention, and not by nature: opposed to natural.
• Imperative; laid down as a command to be followed without question or discretion: as, positive orders.
• Unquestionable; indubitable; certain; hence, experiential.
• Confident; fully assured.
• Over-confident in opinion and assertion; dogmatic.
• Actually or really officiating or discharging the duties of an office.
• Not reversed.
• Not comparative.
• noun That which settles by absolute appointment.
• noun That which is capable of being affirmed; reality.
• noun In grammar, the positive degree.