canard (n.)Related entries & more
"absurd or fabricated story intended as an imposition," 1851, perhaps 1843, from French canard "a hoax," literally "a duck" (from Old French quanart, probably echoic of a duck's quack); said by Littré to be from the phrase vendre un canard à moitié "to half-sell a duck," thus, perhaps from some long-forgotten joke, "to cheat." But also compare quack (n.1).
cancan (n.)Related entries & more
also can-can, "A kind of dance performed in low resorts by men and women, who indulge in extravagant postures and lascivious gestures" [Century Dictionary, 1895], 1848, from French, a slang or cant term possibly from can, a French children's word for "duck" (see canard), via some notion of "waddling" too obscure or obscene to attempt to disentangle here. Or perhaps from French cancan (16c.) "noise, disturbance," echoic of quacking.