1.  abnormality(n = noun.state) abnormalcy - an abnormal physical condition resulting from defective genes or developmental deficiencies;
is a kind of physical condition, physiological condition, physiological state
has particulars: acardia, acephalia, acephalism, acephaly, acorea, acromicria, acromikria, acromphalus, amastia, aneuploidy, anorchia, anorchidism, anorchism, asynclitism, obliquity, atresia, brachydactylia, brachydactyly, cryptorchidism, cryptorchidy, cryptorchism, deviated septum, dextrocardia, ectrodactyly, erethism, fetal distress, foetal distress, hepatomegaly, megalohepatia, inversion, heterotaxy, transposition, pneumothorax, macrencephaly, hydatid mole, hydatidiform mole, molar pregnancy, hydramnios, hypervitaminosis, hypospadias, lagophthalmos, mental abnormality, nanophthalmos, palmature, dysplasia, hydrocephalus, hydrocephaly, abrachia, progeria, atypicality, untypicality, arrested development, fixation, infantile fixation, regression, aberrance, aberrancy, aberration, deviance, cyclopia, spinal curvature, subnormality, anomalousness, anomaly, gynecomastia, infantilism, macrocephaly, megacephaly, megalocephaly, microbrachia, microcephalus, microcephaly, nanocephaly, pachycheilia, phimosis, irritation, retroflection, retroflexion, retroversion, sequela, squint, strabismus, torticollis, wryneck, varix
Antonym: normality
Derived form adjective abnormal₁

2.  abnormality(n = noun.cognition) mental defectiveness - retardation sufficient to fall outside the normal range of intelligence;
is a kind of backwardness, mental retardation, retardation, slowness, subnormality
has particulars: feeblemindedness
Derived form adjective abnormal₂

3.  abnormality(n = noun.attribute) freakishness - marked strangeness as a consequence of being abnormal;
is a kind of strangeness, unfamiliarity

4.  abnormality(n = noun.act) irregularity - behavior that breaches the rule or etiquette or custom or morality;
is a kind of misbehavior, misbehaviour, misdeed
has particulars: deviance, deviation
Derived form adjective abnormal₁

1.  The state or quality of being abnormal; variation; irregularity. Darwin. [1913 Webster]

2.  Something abnormal. [1913 Webster]

abnormality, n. (pl. -ies)
1 a an abnormal quality, occurrence, etc. b the state of being abnormal.
2 a physical irregularity.

N  unconformity, nonconformity, unconformity, disconformity, unconventionality, informality, abnormity, abnormality, anomaly, anomalousness, exception, peculiarity, infraction of law, breach, of law, violation of law, violation of custom, violation of usage, infringement of law, infringement of custom, infringement of usage, teratism, eccentricity, bizarrerie, oddity, je ne sais quoi, monster, monstrosity, rarity, freak, freak of Nature, weirdo, mutant, rouser, snorter, individuality, idiosyncrasy, originality, mannerism, aberration, irregularity, variety, singularity, exemption, salvo, nonconformist, nondescript, character, original, nonesuch, nonsuch, monster, prodigy, wonder, miracle, curiosity, flying fish, black sheep, black swan, lusus naturae, rara avis, queer fish, mongrel, random breed, half-caste, half-blood, half-breed, metis, crossbreed, hybrid, mule, hinny, mulatto, tertium quid, hermaphrodite, phoenix, chimera, hydra, sphinx, minotaur, griffin, griffon, centaur, saggittary, kraken, cockatrice, wyvern, roc, dragon, sea serpent, mermaid, merman, merfolk, unicorn, Cyclops, men whose heads do grow beneath their shoulders, teratology, fish out of water, neither one thing nor another, neither fish nor fowl, neither fish flesh nor fowl nor good red herring, one in a million, one in a way, one in a thousand, outcast, outlaw, off the beaten track, oasis, uncomformable, exceptional, abnormal, abnormous, anomalous, anomalistic, out of order, out of place, out of keeping, out of tune, out of one's element, irregular, arbitrary, teratogenic, lawless, informal, aberrant, stray, wandering, wanton, peculiar, exclusive, unnatural, eccentric, egregious, out of the beaten track, off the beaten track, out of the common, out of the common run, beyond the pale of, out of the pale of, misplaced, funny, unusual, unaccustomed, uncustomary, unwonted, uncommon, rare, curious, odd, extraordinary, out of the ordinary, strange, monstrous, wonderful, unexpected, unaccountable, outre, out of the way, remarkable, noteworthy, queer, quaint, nondescript, none such, sui generis, unfashionable, fantastic, grotesque, bizarre, outlandish, exotic, tombe des nues, preternatural, denaturalized, heterogeneous, heteroclite, amorphous, mongrel, amphibious, epicene, half blood, hybrid, androgynous, androgynal, asymmetric, adelomorphous, bisexual, hermaphrodite, monoclinous, qualified, singular, unique, one-of-a-kind, newfangled, novel, non-classical, original, unconventional, unheard of, unfamiliar, undescribed, unprecedented, unparalleled, unexampled, unconformably, except, unless, save barring, beside, without, save and except, let alone, however, yet, but, once in a blue moon, once in a million years, Int, what on earth!, what in the world!, What the devil!, Holy cow!, Can you top that?, Sacre bleu, never was seen the like, never was heard the like, never was known the like, I could hardly believe it, I saw it, but I didn't believe it.

chrosomal abnormality, congenital abnormality, genetic abnormality, mental abnormality