Antonyms for great

excellent, skillful:

detestable, common, conventional, rotten, inconsiderable, plain, unamazing, imperfect, expected, unpleasant, ok, usual, flawed.

important, celebrated:

bad, unimpressive, inconspicuous, subordinate, unremarkable, auxiliary, ordinary, secondary, unnecessary, contemptible, minor, nonessential, inferior, inessential, extra.

very large:

ignorant, low, unskilled, small, undignified, few, mild, menial, short, insignificant, unknown, uncelebrated, miniature, stupid, minute, infamous, weak, moderate, limited, little, soft, powerless, poor, teeny, unimportant, tiny, thin.

noun:

crude, weak, incapable, squalid, discreditable, last, least, little bitty, incompetent, inept, loath, untaught, unable, inefficient, subordinate, inexpert, lukewarm, incurious, unconcerned, knavish, short-term, untrained, sudden, impermanent, lackadaisical, languorous, impassive, artless, hateful, uneager, momentary, sorry, subsidiary, untutored, shortened, inexperienced, sordid, unwilling, rough, repulsive, spiritless, offensive, petite, small-minded, detestable, rude, would-be, junior, awkward, casual, heavy-handed, fleeting, apathetic, ignominious, clumsy, abominable, abrupt, beginning, dirty, shortish, new, unprofessional, hesitant, pint-size, unfitted, unschooled, insouciant, paltry, petty, ham-fisted, short-lived, uninterested, degraded, mean, condensed, ephemeral, untried, debased, primitive, scanty, jackleg, short-range, transient, reluctant, halfhearted, ham-handed, plain, green, detached, secondary, nonpregnant, unqualified, disinterested, degrading, abbreviated, mini, dwarf, low-grade, unenthusiastic, unpolished, nonchalant, transitory, ineffective, ugly, lowercase, humiliating, unseasoned, unskilled, untalented, amateurish, untested, collateral, ineffectual, amateur, aloof, illegitimate, degenerate, languid, raw, unfit, coarse, unskillful, dastardly, lower class, disinclined, Ungifted, vicious, averse.