1.  monstrosity(n = noun.person) freak, lusus naturae, monster - a person or animal that is markedly unusual or deformed;
is a kind of mutant, mutation, sport, variation
has particulars: leviathan
Derived forms adjective monstrous₃, adjective monstrous₁

2.  monstrosity(n = noun.event) - something hideous or frightful; "they regarded the atom bomb as a monstrosity"
is a kind of malformation, miscreation
Derived form adjective monstrous₂

   The state of being monstrous, or out of the common order of nature; that which is monstrous; a monster. South. [1913 Webster]
"A monstrosity never changes the name or affects the immutability of a species." [1913 Webster]

monstrosity, n. (pl. -ies)
1 a huge or outrageous thing.
2 monstrousness.
3 = MONSTER 3.

Etymology:
LL monstrositas (as MONSTROUS)

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.

N  ridiculousness, comicality, oddity, extravagance, drollery, farce, comedy, burlesque, buffoonery, frippery, doggerel verses, absurdity, bombast, anticlimax, bathos, eccentricity, monstrosity, laughingstock, ridiculous, ludicrous, comical, droll, funny, laughable, pour rire, grotesque, farcical, odd, whimsical, whimsical as a dancing bear, fanciful, fantastic, queer, rum, quizzical, quaint, bizarre, screaming, eccentric, strange, outlandish, out of the way, baroque, weird, awkward, extravagant, outre, monstrous, preposterous, bombastic, inflated, stilted, burlesque, mock heroic, drollish, seriocomic, tragicomic, gimcrack, contemptible, doggerel, ironical, risible, risum teneatis amici, rideret Heraclitus, du sublime au ridicule il n'y a qu'un pas.

N  size, magnitude, dimension, bulk, volume, largeness, greatness, expanse, amplitude, mass, proportions, capacity, tonnage, tunnage, cordage, caliber, scantling, turgidity, corpulence, obesity, plumpness, embonpoint, corporation, flesh and blood, lustihood, hugeness, enormity, immensity, monstrosity, giant, Brobdingnagian, Antaeus, Goliath, Gog and Magog, Gargantua, monster, mammoth, Cyclops, cachalot, whale, porpoise, behemoth, leviathan, elephant, hippopotamus, colossus, tun, cord, lump, bulk, block, loaf, mass, swad, clod, nugget, bushel, thumper, whooper, spanker, strapper, Triton among the minnows, mountain, mound, heap, largest portion, full size, life size, large, big, great, considerable, bulky, voluminous, ample, massive, massy, capacious, comprehensive, spacious, mighty, towering, fine, magnificent, corpulent, stout, fat, obese, plump, squab, full, lusty, strapping, bouncing, portly, burly, well-fed, full-grown, corn fed, gram fed, stalwart, brawny, fleshy, goodly, in good case, in good condition, in condition, chopping, jolly, chub faced, chubby faced, lubberly, hulky, unwieldy, lumpish, gaunt, spanking, whacking, whopping, walloping, thumping, thundering, hulking, overgrown, puffy, huge, immense, enormous, mighty, vast, vasty, amplitudinous, stupendous, monster, monstrous, humongous, monumental, elephantine, jumbo, mammoth, gigantic, gigantean, giant, giant like, titanic, prodigious, colossal, Cyclopean, Brobdingnagian, Bunyanesque, Herculean, Gargantuan, infinite, large as life, plump as a dumpling, plump as a partridge, fat as a pig, fat as a quail, fat as butter, fat as brawn, fat as bacon, immeasurable, unfathomable, unplumbed, inconceivable, unimaginable, unheard-of, of cosmic proportions, of epic proportions, the mother of all, teh granddaddy of all.

N  distortion, detortion, contortion, twist, crookedness, grimace, deformity, malformation, malconformation, harelip, monstrosity, misproportion, want of symmetry, anamorphosis, ugliness, talipes, teratology, asymmetry, irregularity, distorted, out of shape, irregular, asymmetric, unsymmetric, awry, wry, askew, crooked, not true, not straight, on one side, crump, deformed, harelipped, misshapen, misbegotten, misproportioned, ill proportioned, ill-made, grotesque, monstrous, crooked as a ram's horn, camel backed, hump backed, hunch backed, bunch backed, crook backed, bandy, bandy legged, bow legged, bow kneed, knock kneed, splay footed, club footed, round shouldered, snub nosed, curtailed of one's fair proportions, stumpy, gaunt, bloated, scalene, simous, taliped, talipedic, all manner of ways, crooked as a Virginia fence.