Inconsistent; that cannot subsist with something else. Thus, truth and falsehood are essentially incompatible, as are virtue and vice. A degree of cold that congeals water is incompatible with vegetation. Dissipation is incompatible with health, reputation and virtue.

Irreconcilably different or disagreeing; incongruous; as incompatible tempers.

Legally or constitutionally inconsistent; that cannot be united in the same person, without violating the law or constitution. By our constitution, the offices of a legislator and of a judge are incompatible, as they cannot be held at the same time by the same person.