From Longman Dictionary of Contemporary Englishparentheticalpar‧en‧thet‧i‧cal /ˌpærənˈθetɪkəl◂/ (also parenthetic /-ˈθetɪk◂/) adjective formal ALADDsaid or written while you are talking or writing about something else in order to explain something or add information parenthetical references to his childhood —parenthetically /-kli/ adverb
Examples from the Corpus
parenthetical• The help given by the police department is briefly acknowledged in a parenthetical comment.• For example, Dickens is fond of parenthetical constructions which allow the generalizing authorial voice to interrupt the narrative flow.• To avoid interrupting the flow of the main text, occasional bits of parenthetical material appear as footnotes. 