parenthesis

Meanings

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. A digression; the use of such digressions.
4. 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.

Etymology

Learned borrowing from Late Latin parenthesis (“addition of a letter to a syllable in a word”), itself borrowed from Ancient Greek παρένθεσις (parénthesis, “insertion”). By surface analysis, par- + en- + thesis.