That contradicts something, such as an argument. / That is itself a contradiction. / That is diametrically opposed to something. / Mutually exclusive. / Tending to contradict or oppose, contrarious.

(logic) Either of a pair of propositions, that cannot both be true or both be false.

A microscope that uses the change of phase when light is transmitted or reflected from a transparent or reflective specimen to form an image; used especially to study living cells.

The use of a device or procedure to prevent conception as a result of sexual activity.

(chemistry, physics) the progressive decrease in the radii of atoms of the lanthanide elements as the atomic number increases; evident in various physical properties of the elements and their compounds

A machine that is complicated and precarious. / (figuratively, derogatory or ironic) Any object.

(law) An agreement in which an offeror's offer can be accepted only by the performance of an act by the offeree; a "promise for a performance".

A card game in which four players, forming two partnerships, first bid then play by taking tricks.

plural of contrabassoon

(anatomy) The tensioning of a muscle as it is being lengthened