1. (n.) 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 enclosed within curved lines (see def. 2 below), or dashes.

2. (n.) One of the curved lines () which enclose a parenthetic word or phrase.

anastrophe aside broken thread brokenness chiasmus disconnectedness disconnection discontinuance discontinuation discontinuity discontinuousness discreteness disjunction episode fitfulness hypallage hyperbaton hysteron proteron incoherence incompleteness infix injection insert insertion insinuation intercalation interjection interlineation interlocution intermittence interpolation introduction irregularity metastasis metathesis non sequitur noncontinuance nonlinearity nonseriality nonuniformity obiter dictum palindrome remark side remark synchysis tmesis tossing-in