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bracket (v.)[bracket 词源字典]: 1797, of printed matter, "to enclose in brackets," from bracket (n.). Also, "to couple or connect with a brace" (1827), also figurative, "to couple one thing with another" in writing (1807). Artillery rangefinding sense is from 1903, from the noun (1891) in the specialized sense "distance between the ranges of two shells, one under and one over the object." Related: Bracketed; bracketing. In home-building and joinery, bracketed is attested by 1801.[bracket etymology, bracket origin, 英语词源]
parenthesis (n.): 1540s, "words, clauses, etc. inserted into a sentence," from Middle French parenthèse (15c.), from Late 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 "put, place" (see theme). Sense extension by 1715 from the inserted words to the curved brackets that indicate the words inserted.
A wooden parenthesis; the pillory. An iron parenthesis; a prison. ["Dictionary of Buckish Slang, University Wit and Pickpocket Eloquence," London, 1811]