Words for "error" in most Indo-European languages originally meant "wander, go astray" (for example Greek plane in the New Testament, Old Norse villa, Lithuanian klaida, Sanskrit bhrama-), but Irish has dearmad "error," from dermat "a forgetting."
1580s, "mistake, error, a going wrong;" 1610s, "misbehavior, wrong or perverse course of conduct;" see miscarry + -age. In pathology, the meaning "untimely delivery" is from 1660s, on the notion of "fail to reach the intended result." Miscarriage of justice is from 1875, from the "going wrong" sense.
"slight sin, petty crime or fault," 1590s (earlier in corrupt form peccadilian, 1520s), from Spanish pecadillo, diminutive of pecado "a sin," from Latin peccatum "a sin, fault, error," noun use of neuter past participle of peccare "to miss, mistake, make a mistake, do amiss; transgress, offend, be licentious, sin," a word of uncertain origin.
Watkins traces it to PIE *ped-ko-, suffixed form of *ped- "to walk, stumble, impair," from root *ped- "foot." But de Vaan is suspicious: "there is no reference to feet in the meaning of peccare. And to 'make a faux pas' ... would hardly be rendered by the word for 'foot', but rather by 'walking.' " He finds a derivation from the root *pet- "to fall" via *pet-ko- "a fall, error" to be "better semantically, but the addition of *-ko- to the bare root seems strange."
"to turn up with or as with a plow," late 14c., plouen, from plow (n.). There is an apparent reference from c. 1200, of fish, perhaps meaning "to make furrows on the surface of the water," but it might be a mistake for play. Transferred sense of "traverse like a plow" is from 1580s. Related: Plowed; plowing.