• WordNet 3.6
    • n parenthesis a message that departs from the main subject
    • n parenthesis either of two punctuation marks (or) used to enclose textual material
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Webster's Revised Unabridged Dictionary
    • Parenthesis A word, phrase, or sentence, by way of comment or explanation, inserted in, or attached to, a sentence which would be grammatically complete without it. It is usually inclosed within curved lines (see def. 2 below), or dashes. "Seldom mentioned without a derogatory parenthesis .""Don't suffer every occasional thought to carry you away into a long parenthesis ."
    • Parenthesis (Print) One of the curved lines () which inclose a parenthetic word or phrase.
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Century Dictionary and Cyclopedia
    • n parenthesis An explanatory or qualifying clause, sentence, or paragraph inserted in another sentence or in the course of a longer passage, without being grammatically connected with it. It is regularly included by two upright curves facing each other (also called parentheses), or the variant form of them called brackets, but frequently by dashes, and even by commas. The quotation from Dryden given below contains a parenthesis.
    • n parenthesis The upright curves ( ) collectively, or either of them separately, used by printers and writers to mark off an interjected explanatory clause or qualifying remark: as, to place a word or clause in parenthesis or within parentheses. The parentheses ( ), including the square form [ ] also called crotchets and now usually brackets, were formerly (as in the first quotation under def. 1) used to separate a word or words typographically, where quotation-marks are now used. In phonetic discussions (Ellis, Sweet, etc.) the curves are often used for a similar purpose, to indicate that the letters of the words so inclosed have a fixed phonetic value, according to a system previously explained. The curves are also used to inclose small marks and letters, and figures of reference, in order to make them more distinct to the eye.
    • n parenthesis An interval; a break; an episode.
    • n parenthesis Abbreviated par.
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Chambers's Twentieth Century Dictionary
    • n Parenthesis pa-ren′the-sis a word, phrase, or sentence put in or inserted in another which is grammatically complete without it:
    • n Parenthesis pa-ren′the-sis (pl.) the marks ( ) used to mark off a parenthesis
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  • Sebastien-Roch Nicolas De Chamfort
    “The art of the parenthesis is one of the greatest secrets of eloquence in Society.”


Webster's Revised Unabridged Dictionary
NL., fr. Gr. pare`nqesis, fr. parentiqe`nai to put in beside, insert; para` beside + 'en in + tiqe`nai to put, place. See Para- En-, 2, and Thesis
Chambers's Twentieth Century Dictionary
Gr.,—para, beside, en, in, thesis, a placing—tithenai, to place.


In literature:

It is worth remarking, by way of parenthesis, that Herbert's father was a gentleman.
"The Book of Business Etiquette" by Nella Henney
Then there follows what clearly seems to be a parenthesis fitting in just before the great earthquake.
"Quiet Talks on the Crowned Christ of Revelation" by S. D. Gordon
The figures in parenthesis after the title of a story refer to the volume and page number of the magazine.
"The Best Short Stories of 1919" by Various
I don't treat the whole human race, trooping past my breakfast, as a parenthesis in my own mind.
"The Lost Art of Reading" by Gerald Stanley Lee
I will quote the two following cases which are very characteristic, but here I must insert a few remarks in parenthesis.
"Self Mastery Through Conscious Autosuggestion" by Emile Coué
Stage directions should always be in parenthesis.
"The Art of Stage Dancing" by Ned Wayburn
The parenthesis must not appear on the slips.
"Breakfasts and Teas" by Paul Pierce
That was a parenthesis, soon disposed of.
"When Ghost Meets Ghost" by William Frend De Morgan
You have to defend yourself, paragraph by paragraph, parenthesis within parenthesis.
"Hazlitt on English Literature" by Jacob Zeitlin
It seemed to be a part of his mode of thinking, this occasional parenthesis of silence.
"Aliens" by William McFee

In poetry:

("That's exactly the method," the Bellman bold
In a hasty parenthesis cried,
"That's exactly the way I have always been told
That the capture of Snarks should be tried!")
"The Hunting Of The Snark " by Lewis Carroll
("That's exactly the method," the Bellman bold
In a hasty parenthesis cried,
"That's exactly the way I have always been told
That the capture of Snarks should be tried!")
"Fit The Third - The Baker's Tale" by Lewis Carroll
What I want back is what I was
Before the bed, before the knife,
Before the brooch-pin and the salve
Fixed me in this parenthesis;
Horses fluent in the wind,
A place, a time gone out of mind.
"The Eye-Mote" by Sylvia Plath

In news:

For those items with a parenthesis and a number, it means that organization has more than one service project approved for The Initiative.
Reflection, joy, and angst for the colon-dash-parenthesis.
Charles Krauthammer / The choice: European-style socialism or historical parenthesis .
Matinee time-schedules are denoted within "( )" parenthesis.

In science:

The two entries in parenthesis refer respectively to left and right movers and the signs correspond to the choice of GSO pro jection.
AdS/CFT Correspondence and Type 0 String Theory
The uncorrected values are given in parenthesis (see text).
Experimental study of a proximity focusing Cherenkov counter prototype for the AMS experiment
In fig. 1 the function G(z , θ) (the expression in parenthesis) is plotted for τ = 1.
Products of Random Matrices
Numbers between parenthesis are their periods in days.
A revised calibration of the Mv-W(OI 7774) relationship using Hipparcos data: Its application to Cepheids and evolved stars
All along this work we will use the convention that the arguments in the parenthesis define the space we are working in, thus ψ(u) is the Laplace transform of ψ(t).
Aging Continuous Time Random Walks