trifler(n = noun.person) - one who behaves lightly or not seriously;
is a kind of bum, do-nothing, idler, layabout, loafer
Derived form verb trifle₂

   One who trifles. Waterland. [1913 Webster]

N  neglect, carelessness, trifling, negligence, omission, oversight, laches, default, supineness, inattention, nonchalance, imprudence, recklessness, slovenliness improvidence, noncompletion, inexactness, paralipsis, paralepsis, paraleipsis (in rhetoric), trifler, waiter on Providence, Micawber, neglecting, unmindful, negligent, neglectful, heedless, careless, thoughtless, perfunctory, remiss, feebleness, inconsiderate, uncircumspect, incircumspect, off one's guard, unwary, unwatchful, unguarded, offhand, supine, inattentive, insouciant, imprudent, reckless, slovenly inexact, improvident, neglected, unheeded, uncared-for, unperceived, unseen, unobserved, unnoticed, unnoted, unmarked, unattended to, unthought of, unregarded, unremarked, unmissed, shunted, shelved, unexamined, unstudied, unsearched, unscanned, unweighed, unsifted, unexplored, abandoned, buried in a napkin, hid under a bushel, negligently, hand over head, anyhow, in an unguarded moment, per incuriam, Int, never mind, no matter, let it pass, out of sight, out of mind.

N  fool, idiot, tomfool, wiseacre, simpleton, witling, dizzard, donkey, ass, ninny, ninnyhammer, chowderhead, chucklehead, dolt, booby, Tom Noddy, looby, hoddy-doddy, noddy, nonny, noodle, nizy, owl, goose, goosecap, imbecile, gaby, radoteur, nincompoop, badaud, zany, trifler, babbler, pretty fellow, natural, niais, child, baby, infant, innocent, milksop, sop, oaf, lout, loon, lown, dullard, doodle, calf, colt, buzzard, block, put, stick, stock, numps, tony, bull head, dunderhead, addlehead, blockhead, dullhead, loggerhead, jolthead, jolterhead, beetlehead, beetlebrain, grosshead, muttonhead, noodlehead, giddyhead, numbskull, thickskull, lackbrain, shallowbrain, dimwit, halfwit, lackwit, dunderpate, lunkhead sawney, gowk, clod, clod-hopper, clod-poll, clot-poll, clot-pate, bull calf, gawk, Gothamite, lummox, rube, men of Boeotia, wise men of Gotham, un sot a triple etage, sot, jobbernowl, changeling, mooncalf, gobemouche, dotard, driveler, old fogey, old woman, crock, crone, grandmother, cotquean, henhussy, incompetent (insanity), greenhorn, dunce, lubber, madman, one who will not set the Thames on fire, one who did not invent gunpowder, qui n'a pas invente' la poudre, no conjuror, fortuna favet fatuis, les fous font les festinas et les sages les mangen, nomina stultorum parietibus harrent, stultorum plena sunt omnia.