Synonyms for Derangement:

n.

brainsickness, insaneness, sane, mental illness, psychopathy. act (noun)
overthrow, upset.
confusion (noun)
jumble, muddle, disorder.
derangement (noun)
overthrow, unbalance, upset, mental unsoundness.
disorder (noun)
disarray, inexactness, confusion, anarchism, muddlement, disorder, lawlessness, disintegration, indistinctness, disorganization, looseness, amorphousness, disconnectedness, obscurity, commotion, turmoil, clutter, entropy, incoherence, indefiniteness, deformity, disorderliness, laxity, fuzziness, unevenness, formlessness, frenzy, perturbation, messiness, anarchy, mess, chaos, dishevel, insanity, shapelessness, tumult, inchoateness, discomposure, disarrangement.
emotional disorder (noun)
mental illness.
insanity (noun)
lunacy, hallucination, mania, neurosis, dementia, brain-sickness, feverishness, craziness, delirium, psychosis, battiness, hysteria, madness, nuttiness, kookiness.
psychopathy (noun)
psychopathy.
state (noun)
mental unsoundness, unbalance.
unconformity (noun)
anomaly, curiosity, impropriety, freakishness, aberrance, unfamiliarity, uniqueness, peculiarity, aberration, divergence, difference, eccentricity, singularity, inconsistency, outlandishness, strangeness, deviation, idiosyncrasy, nonconformity, quirkiness, incongruity, unconventionality, exception, abnormality, oddity, incompatibility, uncommonness, irregularity, funniness.

Other synonyms:

mental illness, confusedness, disorderedness, psychopathy, brainsickness, insaneness, topsy-turviness. snafu. scramble. mix up. Other relevant words:
scramble, mental illness, disorderedness, jumble, overthrow, snafu, muss, psychopathy, tumble, unbalance, mental unsoundness, upset, confusedness, brainsickness, insaneness, topsy-turviness, muddle.

Usage examples for derangement

  1. There has been little doubt at any time of the derangement of that unfortunate man. – The Attempted Assassination of ex-President Theodore Roosevelt by Oliver Remey Henry Cochems Wheeler Bloodgood
  2. There is a pathetic exception in the outward lives of so many men of genius, the bloom being, to the instructed eye, only the indication of some subtle nervous derangement only the forerunner of decay. – Chopin: The Man and His Music by James Huneker
  3. In either case, your father is in a state of nervous derangement which is likely to lead to serious results- unless he takes the advice that I gave him when he last consulted me. – The Legacy of Cain by Wilkie Collins