Etymology
Advertisement
coot (n.)

late 14c., cote, used for various diving water fowl (now limited to Fulica atra and, in North America, F. americana), of uncertain origin. Perhaps from an unrecorded Old English word, or perhaps from Low German (compare Dutch meercoet "lake coot"). Meaning "silly person, fool" is attested from 1766.

Related entries & more 
Advertisement
mug (v.1)

"to beat up," 1818, originally "to strike the face" (in pugilism), from mug (n.2) "face." The general meaning "attack" is attested by 1846, and "attack to rob" by 1864. Perhaps influenced by thieves' slang mug "dupe, fool, sucker" (1851). Related: Mugged; mugging.

Related entries & more 
dodo (n.)

1620s, massive, flightless, defenseless bird (Didus ineptus) of Mauritius island, said to be from Portuguese doudo "fool, simpleton," an insult applied by Portuguese sailors to the awkward creatures. The last record of a living one is from July 1681. Applied in English to stupid persons by 1886. Compare booby.

Related entries & more 
ninny (n.)

"simpleton, fool," 1590s, perhaps a misdivision of an innocent (see N for other examples), or from the pet form of the proper name Innocent, with sense influenced by the name's literal meaning. There may be some influence in the word of Italian ninno "baby, child" (cognate with Spanish niño). Related: Niniversity "school for idiots" (1580s).

Related entries & more 
sot (n.)
late Old English sott "stupid person, fool," from Old French sot, from Gallo-Roman *sott- (probably related to Medieval Latin sottus, c.800), of uncertain origin, with cognates from Portugal to Germany. Surviving meaning "one who is stupefied with drink" first recorded 1590s. As a verb, it is attested from c. 1200, but usually besot.
Related entries & more 
Advertisement
cockade (n.)

"clasp, button, etc. used to secure the cock of a hat," hence "any knot or badge worn on a hat," especially as a sign of political adherence, 1709, earlier cockard (1650s), from French cocarde (16c.), fem. of cocard (Old French cocart) "foolishly proud, cocky," as a noun, "idiot, fool;" an allusive extension from coq (see cock (n.1)).

Related entries & more 
fop (n.)

mid-15c., "foolish person," of unknown origin, perhaps related to obsolete verb fop "make a fool of," from a continental source akin to German foppen "jeer at, make a fool of." Sense of "dandy, coxcomb, man ostentatiously nice in manner and appearance" is from 1670s, perhaps given in derision by those who thought such things foolish. The 18c. was their period of greatest florescense. The junior variety was a fopling (1680s).

His was the sumptuous age of powder and patches. He was especially dainty in the matters of sword-knots, shoe-buckles, and lace ruffles. He was ablaze with jewelry, took snuff with an incomparable air out of a box studded with diamonds, and excelled in the "nice conduct of a clouded cane." [Charles J. Dunphie, "Fops and Foppery," New York, 1876]
Related entries & more 
bamboozle (v.)

"to cheat, trick, swindle," 1703, originally a slang or cant word, of unknown origin. Perhaps Scottish from bombaze, bumbaze "confound, perplex," or related to bombast, or related to French embabouiner "to make a fool (literally 'baboon') of." Wedgwood suggests Italian bambolo, bamboccio, bambocciolo "a young babe," extended by metonymy to mean "an old dotard or babish gull." Related: Bamboozled; bamboozler; bamboozling. As a noun from 1703.

Related entries & more 
dotard (n.)

late 14c., "imbecile, one who is in dotage or second childhood;" see dote (v.) + -ard. Sense of "one who dotes, one who is foolishly fond" (c. 1600) is now rare or obsolete. Other noun derivatives of dote, all in the sense "fool, simpleton" in Middle English were dotel (late 14c.), doterel (late 15c.), doti-poll (c. 1400; see doddypoll).

Related entries & more 
loco (adj.)
"mad, crazy," 1844, American English, from Spanish loco (adj.) "insane," of uncertain origin, perhaps from Arabic lauqa, fem. of 'alwaq "fool, crazy person." Loco-weed was the name given to species of western U.S. plants that cause cattle and horse diseases that make them stagger and act strangely. But the adjective seems to be the older word.
Related entries & more 

Page 5