not compatible; unable to exist together in harmony

She asked for a divorce because they were utterly incompatible.

contrary or opposed in character; discordant

incompatible colors.

that cannot coexist or be conjoined.

Logic .

(of two or more propositions) unable to be true simultaneously.

(of two or more attributes of an object) unable to belong to the object simultaneously; inconsistent.

(of positions, functions, ranks, etc.) unable to be held simultaneously by one person.

Medicine/Medical . of or pertaining to biological substances that interfere with one another physiologically, as different types of blood in a transfusion.

Pharmacology . of or pertaining to drugs that interfere with one another chemically or physiologically and therefore cannot be mixed or prescribed together.

Usually, incompatibles. incompatible persons or things.

an incompatible drug or the like.

incompatibles, Logic .

two or more propositions that cannot be true simultaneously.

two or more attributes that cannot simultaneously belong to the same object.

noun

conflict , discordance , animosity , disagreement , opposition , difference , discrepance , discrepancy , disparity , incongruity , inconsistency