solecism(n = noun.act) faux pas, gaffe, gaucherie, slip - a socially awkward or tactless act;
is a kind of bloomer, blooper, blunder, boner, boo-boo, botch, bungle, flub, foul-up, fuckup, pratfall

1.  An impropriety or incongruity of language in the combination of words or parts of a sentence; esp., deviation from the idiom of a language or from the rules of syntax. [1913 Webster]
"A barbarism may be in one word; a solecism must be of more." [1913 Webster]

2.  Any inconsistency, unfitness, absurdity, or impropriety, as in deeds or manners. [1913 Webster]
"Cæsar, by dismissing his guards and retaining his power, committed a dangerous solecism in politics." [1913 Webster]
"The idea of having committed the slightest solecism in politeness was agony to him." [1913 Webster]

solecism, n.
1 a mistake of grammar or idiom; a blunder in the manner of speaking or writing.
2 a piece of bad manners or incorrect behaviour.

Derivative:
solecist n. solecistic adj.

Etymology:
F sol{eacute}cisme or L soloecismus f. Gk soloikismos f. soloikos speaking incorrectly

N  solecism, bad grammar, false grammar, faulty grammar, slip of the pen, slip of the tongue, lapsus linguae, slipslop, bull, barbarism, impropriety, ungrammatical, incorrect, inaccurate, faulty, improper, incongruous, solecistic, solecistical.

N  inelegance, stiffness, unlettered Muse, barbarism, slang, solecism, mannerism, euphuism, fustian, cacophony, words that break the teeth, words that dislocate the jaw, marinism, inelegant, graceless, ungraceful, harsh, abrupt, dry, stiff, cramped, formal, guinde, forced, labored, artificial, mannered, ponderous, awkward, uncourtly, unpolished, turgid, affected, euphuistic, barbarous, uncouth, grotesque, rude, crude, halting, offensive to ears polite, Spoken Language.

N  intuition, instinct, association, hunch, gut feeling, presentiment, premonition, rule of thumb, superstition, astrology, faith (supposition), sophistry, paralogy, perversion, casuistry, jesuitry, equivocation, evasion, chicane, chicanery, quiddet, quiddity, mystification, special pleading, speciousness, nonsense, word sense, tongue sense, false reasoning, vicious reasoning, circular reasoning, petitio principii, ignoratio elenchi, post hoc ergo propter hoc, non sequitur, ignotum per ignotius, misjudgment, false teaching, sophism, solecism, paralogism, quibble, quirk, elenchus, elench, fallacy, quodlibet, subterfuge, subtlety, quillet, inconsistency, antilogy, a delusion, a mockery, and a snare, claptrap, cant, mere words, lame and impotent conclusion, meshes of sophistry, cobwebs of sophistry, flaw in an argument, weak point, bad case, overrefinement, hairsplitting, intuitive, instinctive, impulsive, independent of reason, anterior to reason, gratuitous, hazarded, unconnected, unreasonable, illogical, false, unsound, invalid, unwarranted, not following, inconsequent, inconsequential, inconsistent, absonous, absonant, unscientific, untenable, inconclusive, incorrect, fallacious, fallible, groundless, unproved, non sequitur, it does not follow, deceptive, sophistical, jesuitical, illusive, illusory, specious, hollow, plausible, ad captandum, evasive, irrelevant, weak, feeble, poor, flimsy, loose, vague, irrational, nonsensical, foolish, frivolous, pettifogging, quibbling, finespun, overrefined, at the end of one's tether, au bout de son latin, intuitively, by intuition, illogically, non constat, that goes for nothing.