discord

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Lack of agreement among persons, groups, or things.
2. n. Tension or strife resulting from a lack of agreement; dissension.
3. n. A confused or harsh sound or mingling of sounds.
4. n. Music An inharmonious combination of simultaneously sounded tones; a dissonance.
5. v. To fail to agree or harmonize; clash.

Century Dictionary and Cyclopedia

1. n. Want of concord or harmony between persons or things; disagreement of relations; especially, as applied to persons, difference of opinions; variance; opposition; contention; strife; any disagreement which produces passion, contest, disputes, litigation, or war.
2. n. In music: The combination of two tones that are inharmonious with each other, or inconclusive in combined effect; a dissonance.
3. n. The interval between two such tones; any interval not a unison, octave, perfect fifth, perfect fourth, major or minor third, or major or minor sixth. In medieval music all but the first three of the above intervals were at first regarded as discords.
4. n. Either of the two tones forming such an interval.
5. n. A chord containing such intervals.See dissonance.
6. n. Hence—3. Any confused noise; a mingling or clashing of sounds; a harsh clang or uproar.
7. To disagree; jar; clash.
8. To be discordant or dissonant.

Wiktionary

1. n. Lack of concord, agreement or harmony among persons, groups, or things.
2. n. Tension or strife resulting from a lack of agreement; dissension.
3. n. music An inharmonious combination of simultaneously sounded tones; a dissonance.
4. n. Any harsh noise, or confused mingling of sounds.
5. v. archaic To disagree; to be at variance; to fail to agree or harmonize; clash.

GNU Webster's 1913

1. n. Want of concord or agreement; absence of unity or harmony in sentiment or action; variance leading to contention and strife; disagreement; -- applied to persons or to things, and to thoughts, feelings, or purposes.
2. n. (Mus.) Union of musical sounds which strikes the ear harshly or disagreeably, owing to the incommensurability of the vibrations which they produce; want of musical concord or harmony; a chord demanding resolution into a concord.
3. v. obsolete To disagree; to be discordant; to jar; to clash; not to suit.

WordNet 3.0

1. v. be different from one another
2. n. a harsh mixture of sounds
3. n. strife resulting from a lack of agreement
4. n. lack of agreement or harmony
5. n. disagreement among those expected to cooperate