Synonyms of unimportant

1 Syllable

zilch, slight, least, zip, null

2 Syllables

low-born, zero, frothy, trifling, slighter, nothing, shoestring, slightest, runter, short-end, minors, placer, minor, niggling, orphic, measlier, deadwood, lightweight, scratcher, substract, wimpy, second, paltrier, little, pettier, pettiest, drossy, shucker, trivial, casual, paltry, petty, piddling, small-time, worthless, measly, no-good

3 Syllables

low-ranking, meaningless, senseless, light-minded, nonserious, futile, seconding, doubletalk, resultless, useless, doublespeak, runner-up, frivolous, no-account, smalltime, unmeaning, second-rate, minute, time-wasting, picayune

4 Syllables

expendable, nonessential, minor-league, dispensable, entry-level, microcosmic, inconsequent, peripheral, perimetric, unhonored, immaterial, negligible, unpurposed, irrelevant, nickel-and-dime, penny-ante, unessential, nugatory, indifferent, unnotable, secondary, ignorable

5 Syllables

insignificant, inconsequential, unnecessary, unconsequential

6 Syllables

inconsiderable