Incapable of associating or blending or of being associated or blended because of disharmony, incongruity, or antagonism: incompatible views on religion.
Impossible to be held simultaneously by one person: the incompatible offices of prosecutor and judge.
Logic That cannot be simultaneously true; mutually exclusive.
Medicine Producing an undesirable effect when used in combination with a particular substance: a medication that is incompatible with alcohol.
Medicine Not immunologically compatible: incompatible blood types.