parentheses

n. the characters ( ), parentheses are used to separate material that is nonessential information in a sentence or additional inormation from the very important information in a sentence; text enclosed in parentheses; act of isolating by parentheses (Syntax)

Parenthesis may be:Parenthesis, either of the curved-bracket ( ) punctuation marks that together make a set of parenthesesParenthesis (rhetoric), parenthetical expression
See more at Wikipedia.org...

Noun
1. either of two punctuation marks (or) used to enclose textual material
(hypernym) punctuation, punctuation mark
2. a message that departs from the main subject
(synonym) digression, aside, excursus, divagation
(hypernym) message, content, subject matter, substance

n. parenthesis, bracket

(pl. )
of Parenthesis