German Pavian "baboon" is from Dutch baviaan, from Middle Dutch baubijn, a borrowing of the Old French word. Century Dictionary says Arabic maimun probably is from the European words.
"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.
late 14c., from Greek hamadryas (plural hamadryades) "wood-nymph," fabled to die with her tree, from hama "together with" (from PIE root *sem- (1) "one; as one, together with") + dryas (plural dryades) "wood nymph," from drus (genitive dryos) "tree," especially "oak" (from PIE root *deru- "be firm, solid, steadfast," with specialized senses "wood, tree"). Use in 19c. biology for a type of butterfly, a type of venomous Indian serpent, and a type of large hairy baboon.
"the largest, most hideous, and most ferocious of the baboons" [OED], 1744, perhaps ultimately from a West African language, but formed into the English components man (n.) + drill (n.4) "baboon," which is of West African origin. The earliest reference reports the name is what the animal was "called by the white men in this country [Sierra Leone], but why it is so called I know not, nor did I ever hear of the Name before, neither can those who call them so tell, except it be for their near Resemblance of a human Creature, though nothing at all like an Ape." [William Smith, "A New Voyage to Guinea"]. French mandrill, Spanish mandril seem to be from English.
1520s, also monkie, munkie, munkye, etc., not found in Middle English (where ape was the usual word); of uncertain origin, but likely from an unrecorded Middle Low German *moneke or Middle Dutch *monnekijn, a colloquial word for "monkey," originally a diminutive of some Romanic word, compare French monne (16c.); Middle Italian monnicchio, from Old Italian monna; Spanish mona "ape, monkey." In a 1498 Low German version of the popular medieval beast story Roman de Renart ("Reynard the Fox"), Moneke is the name given to the son of Martin the Ape; transmission of the word to English might have been via itinerant entertainers from the German states.
The Old French form of the name is Monequin (recorded as Monnekin in a 14c. version from Hainault), which could be a diminutive of some personal name, or it could be from the general Romanic word, which may be ultimately from Arabic maimun "monkey," literally "auspicious," a euphemistic usage because the sight of apes was held by the Arabs to be unlucky [Klein]. The word would have been influenced in Italian by folk etymology from monna "woman," a contraction of ma donna "my lady."
In general, any one of the primates except man and lemurs; in more restricted use, "an anthropoid ape or baboon;" but popularly used especially of the long-tailed species often kept as pets. Monkey has been used affectionately or in pretended disapproval of a child since c. 1600. As the name of a type of modern popular dance, it is attested from 1964.
Monkey suit is from 1876 as a type of child's suit; by 1918 as slang for "fancy dress clothes or uniform." To make a monkey of "make a fool of" is attested from 1851. To have a monkey on one's back "be addicted" is 1930s narcotics slang, though the same phrase in the 1860s meant "to be angry." There is a story in the Sinbad cycle about a tormenting ape-like creature that mounts a man's shoulders and won't get off, which may be the root of the term. In 1890s British slang, to have a monkey up the chimney meant "to have a mortgage on one's house." The Japanese three wise monkeys ("see no evil," etc.) are attested in English by 1891.