"frame of wood erected on a post or pole with holes into which were put the head and hands of an offender who was thus exposed for public derision and abuse," mid-14c., pillorie (attested in Anglo-Latin from late 12c., in surnames from mid-13c.), from Old French pilori "pillory" (mid-12c.), which is related to Medieval Latin pilloria, but all are of uncertain origin. Perhaps a diminutive of Latin pila "pillar, stone barrier" (see pillar), but OED finds this proposed derivation "phonologically unsuitable."
c. 1600, "punish by exposure in the pillory," from pillory (n.). Figurative sense of "expose publicly to ridicule, contempt, or abuse" is from 1690s. Related: Pilloried.
1540s, "words, clauses, etc. inserted into a sentence, not grammatically connected to it but explaining or qualifying a word," from French parenthèse (15c.) or directly from Medieval Latin parenthesis "addition of a letter to a syllable in a word," from Greek parenthesis, literally "a putting in beside," from parentithenai "put in beside," from para- "beside" (see para- (1)) + en- "in" + tithenai "to put, to place" (from reduplicated form of PIE root *dhe- "to set, put").
By 1715 the sense was extended from the inserted words to the two upright curved brackets (parentheses) used by printers or writers to indicate the words inserted.
Your first figure of tollerable disorder is [Parenthesis] or by an English name the [Insertour] and is when ye will seeme for larger information or some other purpose, to peece or graffe in the middest of your tale an vnnecessary parcell of speach, which neuerthelesse may be thence without any detriment to the rest. [George Puttenham, "The Arte of English Poesie," 1589]
A wooden parenthesis; the pillory. An iron parenthesis; a prison. ["Dictionary of Buckish Slang, University Wit and Pickpocket Eloquence," London, 1811]
Old English stocc "stump, post, stake, tree trunk, log," also "pillory" (usually plural, stocks), from Proto-Germanic *stauk- "tree trunk" (source also of Old Norse stokkr "block of wood, trunk of a tree," Old Saxon, Old Frisian stok, Middle Dutch stoc "tree trunk, stump," Dutch stok "stick, cane," Old High German stoc "tree trunk, stick," German Stock "stick, cane;" also Dutch stuk, German Stück "piece"), from an extended form of PIE root *(s)teu- (1) "to push, stick, knock, beat" (see steep (adj.)).
Meaning "ancestry, family" (late 14c.) is a figurative use of the "tree trunk" sense (as in family tree). This is also the root of the meaning "heavy part of a tool," and "part of a rifle held against the shoulder" (1540s). Meaning "person as dull and senseless as a block or log" is from c. 1300; hence "a dull recipient of action or notice" (1540s).
Meaning "framework on which a boat was constructed" (early 15c.) led to figurative phrase on stocks "planned and commenced" (1660s). Taking stock "making an inventory" is attested from 1736. Stock, lock, and barrel "the whole of a thing" is recorded from 1817. Stock-still (late 15c.) is literally "as still as a tree trunk."
"pointed stick or post; stick of wood sharpened at one end for driving into the ground, used as part of a fence, as a boundary-mark, as a post to tether an animal to, or as a support for something (a vine, a tent, etc.)," Old English staca "pin, stake," from Proto-Germanic *stakon (source also of Old Norse stiaki "a stake, pole, candlestick,"Old Frisian stake, Middle Dutch stake, Dutch staak "a stake, post," Middle Low German stake "a stake, post, pillory, prison"), from PIE root *steg- (1) "pole, stick." The Germanic word was borrowed in Romanic (Spanish and Portuguese estaca "a stake," Old French estaque, estache, Italian stacca "a hook"), and was borrowed back as attach.
Meaning "post to which a person condemned to death by burning is bound" is from c. 1200, also "post to which a bear to be baited is tied" (late 14c.). Meaning "vertical bar fixed in a socket or in staples on the edge of the bed of a platform railway-car or of a vehicle to secure the load from rolling off, or, when a loose substance, as gravel, etc., is carried, to hold in place boards which retain the load," is by 1875; hence stake-body as a type of truck (1903).
Pull up stakes was used c. 1400 as "abandon a position" (the allusion is to pulling up the stakes of a tent); the modern American English figurative expression in the sense of "move one's habitation" is by 1703.