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.
One of the curved lines () which inclose a parenthetic word or phrase.
Parenthesis are used to control the order of searching in a database. If you use parenthesis around a phrase including an AND, OR, NOT statement that phrase will be searched for first before the other searching is done.
( ) used as phrase markers in grammar and in mathematics to top
Marks of inclusion (symbols: ( and )).
either of two punctuation marks (or) used to enclose textual material
an explanatory phrase inserted into a sentence that could otherwise exist without this phrase being inserted
an instance of delineated text which can be marked by brackets, dashes, or commas
a word or phrase inserted into a sentence to explain or elaborate
the punctuation marks ( ) used to enclose your own explanatory materials in a phrase or sentence of your own; use sparingly.
a word, clause or even sentence which is inserted into a sentence to which it does not grammatically belong
extra information, given in addition to the main text in a sentence; commonly written in brackets (parentheses), within the sentence
As opposed to  square brackets.
Punctuation marks (usually known as brackets).
In rhetoric, a parenthesis (plural: parentheses; from the Greek word Ï€Î±ÏÎµÎ½Î¸ÎµÏƒÎ¹Ï‚, which comes in turn from words meaning "alongside of" and "to place") is