What's the noun for paren? Here's the word you're looking for.
parenthesis
A clause, phrase or word which is inserted (usually for explanation or amplification) into a passage which is already grammatically complete, and usually marked off with brackets, commas or dashes.
Either of a pair of brackets, especially round brackets, ( and ) (used to enclose parenthetical material in a text).
(rhetoric) A digression; the use of such digressions.
(mathematics) Such brackets as used to clarify expressions by grouping those terms affected by a common operator, or to enclose the components of a vector or the elements of a matrix.
“If there is no other right parenthesis except the outermost one, format control reverts to the left parenthesis at the beginning of the format specification.”
“The order and number of words in our translations will uniformly correspond with the text, and when the meaning is not sufficiently clear it is explained in parenthesis.”
“When the waiter arrived at the table to serve coffee, a parenthesis of silence settled over the table.”
parembole
(rhetoric) A kind of rhetoricalparenthesis. The insertion of something relating to the subject in the middle of a period.
paren
(computing) A parenthesis (bracket used to enclose parenthetical material in text).
“It's like when I idiotically put two or three parentheticals inside each other rather than doing the normal thing and writing out separate sentences!”
“Thus, one crucial feature of pragmatic markers and parentheticals has been claimed to be that they are movable while sentence adverbials are not.”