Antonyms for bad:
serviceable, honest, just, true, first class, solid, superior, great, goodness, wonderful, genuine, functioning, beneficent, slap-up, A1, mild, worthy, moral, virtuous, right, advantageous, decent, noble, nice, good, beneficial, profitable, smashing, comfortable.
Synonyms for bad:
defective, detrimental, poor, unfavorable, inadequate, ill-suited, displeasing, vile, unpleasant, invalid, wretched, wrong, unsatisfactory, inadvisable, black, baneful, unsound, arrant, faulty, irremediable, inferior.
sinister, foul, heinous, nefarious, Fiendish, wicked, monstrous, evil, atrocious, repellent, sinful, revolting, repugnant, terrible, black, baneful, reprehensible, destructive, offensive, loathsome, devilish, damnable, detrimental, calamitous, abominable, disgraceful, hideous, unpropitious, repulsive.
criminal, sinister, felonious, sadistic, improper, perverse, corrupt, indecent, reprehensible, vice, villainous, wrongdoing, lawbreaking, evildoing, immoral, shocking, debauched, wicked, scandalous, base, Misdoing, damnable, black, debased, depraved, devilish, sinful, obnoxious, blameworthy, degenerate, iniquitous.
Sense 1 (noun)
Sense 2 (noun)
Sense 3 (noun)
Sense 4 (noun)
Sense 5 (noun)
Sense 6 (noun)
Sense 9 (noun)
Sense 10 (noun)
Sense 11 (noun)
compromising, dangerous, unendurable, dull, schismatic, prepubescent, bastardized, chapped, obstructive, Gnawing, offending, deficient, libellous, uninviting, difficult, crippling, egregious, defamatory, unenviable, problem, degrading, teenage, dire, off-putting, unleavened, ill-behaved, agonizing, overpowering, teenaged, self-defeating, peccant, catastrophic, thankless, debilitating, fraught, teen, inhospitable, scurrilous, underage, damning, unedifying, dodgy, crummy, costly, unappetizing, slanderous, discreditable, yucky, painfully, punitive, insipid, rancid, excruciating, gross out, chronic, fractious, terribly, shabby, tainted, uneatable, puny, embarrassing, irreparable, intrusive, achy, disruptive, unrewarding, stabbing, unattractive, unpropitious, vexed, touchy, objectionable, pubescent, angry, unmentionable, torturous, contemptible, provocative, agonising, murphy's law, day, burdensome, expensive, troublesome, low-class, irritated, abysmal, sickly, divisive, vice-like, inflamed, hell of a, invidious, contentious, bland, subhuman, third-rate, tendentious.
awesome, sore, acrid, raging, small, chilling, rogue, undesirable, awkward, corrosive, diabolical, inflammatory, itchy, infernal, stiff, burning, slimy, appalling, stinging, putrid, uncongenial, preteen, pungent, violent, lawless, prickly, tasteless, acute, stewed, incendiary, watery, inauspicious, damned, adolescent.
Other synonyms and related words:
badly, iniquity, rotten, unwell, ailing, down, peccant, vicious, sick, ill, indisposed, reprobate, unwholesome, objectionable, naughty, putrid, amiss, spoiled, nasty, unhealthful, noisome, insalubrious, noxious, lousy, awful, unhealthy, dangerous.