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1. Not compatible
   "incompatible personalities"; "incompatible colours"
    
2. Used especially of drugs or muscles that counteract or neutralize each other's effect
   - antagonistic
    
3. Not suitable to your tastes or needs
   "the incompatible roommates were always fighting";
   - uncongenial
    
4. Incapable of being used with or connected to other devices or components without modification
    
5. Of words so related that one contrasts with the other
   "'rich' and 'hard-up' are incompatible terms";
   - contrastive
    
6. (of a couple) not compatible; unsuitably matched
   "protracted anguish of an incompatible union";
   - ill-sorted, mismated, unsuited, ill-assorted, ill-suited
    
7. Not compatible with other facts
   - discrepant
    
8. Not in keeping with what is correct or proper
   "completely incompatible behaviour";
   - inappropriate, out of keeping, unfitting
    
9. Used especially of solids or solutions; incapable of blending into a stable homogeneous mixture

See also: antacid, antagonistic, antiphlogistic, antonymous, clashing, contradictory, different, disagreeable, immiscible, incongruous, inconsistent, inharmonious, mismatched, mutually exclusive, non-miscible, out of line, out of order [Brit], uncongenial, unfriendly, unharmonious, unmixable, unsympathetic

Antonym: compatible, congenial, synergistic

Encyclopedia: Incompatible