noun.an amplifying or explanatory word, phrase, or sentence inserted in a passage from which it is usually set off by punctuation

• explained further in a parenthesis
• The speaker inserted some often amusing parentheses during his speech.

noun.a remark or passage that departs from the theme of a discourse: digression

• The parenthesis of war interrupted the course of his life.
• The plant's common name is followed by its Latin name in parentheses.

noun.interlude, interval