Similar word to zippest:

beside the point, casual, frivolous, frothy, immaterial, inconsequential, inconsiderable, indifferent, insignificant, irrelevant, little, low-ranking, meaningless, minor, minute, negligible, nonessential, nothing, nugatory, null, of no account, of no consequence, paltry, petty, picayune, second-rate, shoestring, slight, trifling, trivial, unnecessary, useless, worthless, zero, zilch, zip