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1. The relation between propositions that cannot both be true at the same time
   - mutual exclusiveness, inconsistency, repugnance
    
2. (immunology) the degree to which the body's immune system will try to reject foreign material (as transfused blood or transplanted tissue)
    
3. The quality of being unable to exist or work in congenial combination

Derived forms: incompatibilities

See also: incompatible

Type of: characteristic, contradictoriness, physical condition, physiological condition, physiological state

Antonym: compatibility