Online Etymology Dictionary

trifle: early 13c., trufle "false or idle tale," later "matter of little importance" (late 13c.), from O.Fr. trufle "mockery," dim. of truffe "deception," of uncertain origin. The verb, in the sense of "treat lightly," is first attested 1520s.
bagatelle: 1630s, "a trifle," from Fr. bagatelle "knicknack, bauble, trinket" (16c.), from It. bagatella "a trifle," dim. of L. baca "berry." As "a piece of light music," it is attested from 1827.
footle: "to trifle," 1892, from dial. footer "to trifle," footy "mean, paltry" (1752), probably from Fr. se foutre "to care nothing," from O.Fr. foutre "to fuck," from L. futuere, originally "to strike, thrust" (cf. confute). But O.E.D. derives the Eng. dial. words from foughty (1600), from Du. vochtig or Dan. fugtig "damp, musty;" related to fog.
falderol: also falderal, folderol, 1701, nonsense refrain in songs; meaning "gewgaw, trifle" is attested from 1820.
piffle: 1847, of unknown origin, perhaps an alteration of trifle, by influence of piddle, etc. Or perhaps onomatopoeic of a puff of air, with a dim. suffix.
whimwham: "whimsical device, trifle," 1529, of unknown origin; perhaps from Scand. (cf. O.N. hvima "to let the eyes wander," Norw. kvima "to flutter"), or else an arbitrary native formation (cf. flim-flam).
fad: 1834, "hobby, pet project;" 1881 as "fashion, craze," perhaps shortened from fiddle-faddle. Or perhaps from Fr. fadaise "trifle, nonsense," ult. from L. fatuus "stupid."
gimcrack: 1618, "showy person," sense of "trifle" first recorded 1839, of uncertain origin, perhaps alteration of gibecrake "a kind of ornament" (1360), perhaps from O.Fr. giber "to rattle, shake" + M.E. crak "sharp noise, crack." In 18c.-19c. it also meant "a person who has a turn for mechanical contrivances."
nil: "nothing," 1833, from L. nil, contraction of nihil, nihilum "nothing," from ne- "not" (see un-) + hilum "small thing, trifle," of unknown origin.
twiddle: c.1540, "to trifle," of unknown origin; of the fingers, first recorded 1676. Fig. phrase twiddle one's thumbs "have nothing to do" is recorded from 1846; to twirl one's thumbs in the same sense is recorded from 1816.
nugatory: "trifling, of no value," c.1600, from L. nugatorius "worthless, futile," from nugator (gen. nugatoris) "jester, trifler," from nugatus, pp. of nugari "to trifle," from nugæ (gen. nugarum) "jokes, jests, trifles," of unknown origin.
burlesque: 1660s, "derisive imitation, grotesque parody," from Fr. burlesque (16c.), from It. burlesco, from burla "joke, fun, mockery," possibly ultimately from L.L. burra "trifle, nonsense," lit. "flock of wool." Modern sense of "variety show featuring striptease" is Amer.Eng., 1870. Originally (1857) "the sketches at the end of minstrel shows." As a verb, from 1670s.
toy (n.): c.1300, "amorous playing, sport," later "piece of fun or entertainment" (c.1500), "thing of little value, trifle" (1530), and "thing for a child to play with" (1586). Of uncertain origin, and there may be more than one word here. Cf. M.Du. toy, Du. tuig "tools, apparatus, stuff, trash," in speeltuig "play-toy, plaything;" Ger. Zeug "stuff, matter, tools," Spielzeug "plaything, toy;" Dan. tøi, Swed. tyg "stuff, gear." The verb is first attested 1529, from the noun.
"If he be merie and toy with any,
His wife will frowne, and words geve manye."
["Song of the Bachelor's Life," 16c.]
fiddle (n.): O.E. fiðele, related to O.N. fiðla, M.Du. vedele, Ger. Fiedel; all probably from M.L. vitula "stringed instrument," perhaps related to L. vitularia "celebrate joyfully," from Vitula, Roman goddess of joy and victory, who probably, like her name, originated among the Sabines. The verb is from late 14c.; the figurative sense of "to act idly" is from 1520s. Related: Fiddling. The word has been relegated to colloquial usage by its more proper cousin, violin, a process encouraged by phraseology such as fiddlestick (15c., originally "the bow of a fiddle;" meaning "nonsense" is from 1620s) and fiddle-faddle (1570s), which is unrelated, being a reduplication of obsolete faddle "to trifle." Fit as a fiddle is from 1610s.
doodle (v.): "scrawl aimlessly," 1935, from dial. doodle, dudle "fritter away time, trifle." It was a noun meaning "simple fellow" from 1620s.
LONGFELLOW: That's a name we made up back home for people who make foolish designs on paper when they're thinking. It's called doodling. Almost everybody's a doodler. Did you ever see a scratch pad in a telephone booth? People draw the most idiotic pictures when they're thinking. Dr. Von Holler, here, could probably think up a long name for it, because he doodles all the time. ["Mr. Deeds Goes to Town," screenplay by Robert Riskin, 1936; based on "Opera Hat," serialized in "American Magazine" beginning May 1935, by Clarence Aldington Kelland]
Related: Doodling. Doodle-bug "type of beetle or larvae" is c.1866, Southern U.S. dialect; the same word was applied 1944 in R.A.F. slang to German V-model flying bombs.
fool (n.): late 13c., from O.Fr. fol "madman, insane person," also an adj. meaning "mad, insane," from L. follis "bellows, leather bag," in V.L. used with a sense of "windbag, empty-headed person" (see follicle). Cf. also Skt. vatula- "insane," lit. "windy, inflated with wind."
"The word has in mod.Eng. a much stronger sense than it had at an earlier period; it has now an implication of insulting contempt which does not in the same degree belong to any of its synonyms, or to the derivative foolish." [OED]
Meaning "jester, court clown" first attested late 14c., though it is not always possible to tell whether the reference is to a professional entertainer or an amusing lunatic on the payroll. As the name of a kind of custard dish, it is attested from 1590s (the food was also called trifle, which may be the source of the name). The verb meaning "to make a fool of" is recorded from 1590s. Related: Fooled; fooling. As an adjective, fool “foolish, silly” is considered modern U.S. colloquial, but it is attested from early 13c. Feast of Fools (early 14c.), from M.L. festum stultorum) refers to the burlesque festival celebrated in some churches on New Year's Day in medieval times. Fool's gold "iron pyrite" is from 1882. Fool's paradise "state of illusory happiness" is from mid-15c. Fool around is 1875 in the sense of "pass time idly," 1970s in sense of "have sexual adventures." Foolosopher, a most useful insult, turns up in a 1549 translation of Erasmus. Fool’s ballocks is described in OED as “an old name” for the green-winged orchid.