incompatible

American Heritage® Dictionary of the English Language, Fourth Edition

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

Century Dictionary and Cyclopedia

1. Not compatible; incapable of harmonizing or agreeing; mutually repelling; incongruous.
2. Specifically That cannot coexist or be conjoined, as mutually repellent substances, or ingredients in a medicine which react on each other, causing precipitation or serious change of composition, or remedies which have opposite medicinal properties. Such substances are distinctively called incompatibles. Synonyms Incompatible, Inconsistent, Incongruous, unsuitable, discordant, irreconcilable. Incompatible has reference to action or active qualities: as, incompatible medicines; those who are of incompatible temper cannot well coöperate. Inconsistent implies a standard, as of truth, right, or fitness: as, it is inconsistent with one's duty or profession. Incongruity is a want of suitableness, matching, or agreement, producing surprise, annoyance, or a sense of the absurd: as, incongruous colors; he had gathered a party of the most incongruous people. Drunkenness is incompatible with efficiency in an official, inconsistent with his manifest duty and perhaps his pledges, and incongruous with the dignity of his place. Inconsistent has somewhat wider uses: as, a man, or his course, or his statements, may be quite inconsistent, one part of his course or one statement furnishing a standard by which judgment is formed.
3. Persons or things that are incompatible with each other. See I., 2.

Wiktionary

1. adj. Of two things: impossible to coexist; not congruous because of differences; irreconcilable; disagreeing.
2. n. medicine, chemistry An incompatible substance; one of a group of things that cannot be placed or used together because of a change of chemical composition or opposing medicinal qualities.

GNU Webster's 1913

1. adj. Not compatible; so differing as to be incapable of harmonious combination or coexistence; inconsistent in thought or being; irreconcilably disagreeing
2. adj. (Chem.) Incapable of being together without mutual reaction or decomposition, as certain medicines.
3. n. (Med. & Chem.) An incompatible substance; esp., in pl., things which can not be placed or used together because of a change of chemical composition or of opposing medicinal qualities.

WordNet 3.0

1. adj. incapable of being used with or connected to other devices or components without modification
2. adj. not compatible
3. adj. not easy to combine harmoniously
4. adj. used especially of solids or solutions; incapable of blending into a stable homogeneous mixture
5. adj. not in keeping with what is correct or proper
6. adj. used especially of drugs or muscles that counteract or neutralize each other's effect
7. adj. not compatible with other facts
8. adj. not suitable to your tastes or needs
9. adj. of words so related that one contrasts with the other