1.  dissonant(s = adj.all) unresolved - characterized by musical dissonance; harmonically unresolved;
Derived forms noun dissonance₂, verb dissonate₂, verb dissonate₁

2.  dissonant(s = adj.all) discordant, disharmonious, inharmonic - lacking in harmony;
Derived form noun dissonance₃

3.  dissonant(s = adj.all) at variance, discrepant - not in accord; "desires at variance with his duty"; "widely discrepant statements"

dissonant, adj.
1 Mus. harsh-toned; unharmonious.
2 incongruous; clashing.

Derivative:
dissonance n. dissonantly adv.

Etymology:
ME f. OF dissonant or L dissonare (as DIS-, sonare sound)

N  discord, disagreement, discord, disaccord, dissidence, dissonance, jar, clash, shock, jarring, jostling, screw loose, variance, difference, dissension, misunderstanding, cross purposes, odds, brouillerie, division, split, rupture, disruption, division in the camp, house divided against itself, disunion, breach, schism, feud, faction, quarrel, dispute, tiff, tracasserie, squabble, altercation, barney, demel_e, snarl, spat, towrow, words, high words, wrangling, jangle, brabble, cross questions and crooked answers, snip-snap, family jars, polemics, litigation, strife, warfare, outbreak, open rupture, declaration of war, broil, brawl, row, racket, hubbub, rixation, embroilment, embranglement, imbroglio, fracas, breach of the peace, piece of work, scrimmage, rumpus, breeze, squall, riot, disturbance, commotion, bear garden, Donnybrook, Donnybrook Fair, subject of dispute, ground of quarrel, battle ground, disputed point, bone of contention, bone to pick, apple of discord, casus belli, question at issue, vexed question, vexata quaestio, brand of discord, troublous times, cat-and-dog life, contentiousness, enmity, hate, Kilkenny cats, disputant, strange bedfellows, discordant, disagreeing, out of tune, ajar, on bad terms, dissentient, unreconciled, unpacified, contentious, quarrelsome, unpacific, gladiatorial, controversial, polemic, disputatious, factious, litigious, litigant, pettifogging, at odds, at loggerheads, at daggers drawn, at variance, at issue, at cross purposes, at sixes and sevens, at feud, at high words, up in arms, together by the ears, in hot water, embroiled, torn, disunited, quot homines tot sententiae, no love lost between them, non nostrum tantas componere lites, Mars gravior sub pace latet, discord, discordance, dissonance, cacophony, want of harmony, caterwauling, harshness, Babel, Dutch concert, cat's concert, marrowbones and cleavers, discordant, dissonant, absonant, out of tune, tuneless, unmusical, untunable, unmelodious, immelodious, unharmonious, inharmonious, singsong, cacophonous, harsh, jarring.