Definition of "parenthesis" in English

noun

1. 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.

2. Either of a pair of brackets, especially (mainly US) round brackets, ( and ) (used to enclose parenthetical material in a text).

3. (rhetoric) A digression; the use of such digressions.

4. (mathematics, logic) 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.