Entry 1 sense Webster, 1913 Adverbial /ăd-vẽrb'-ē-əl/ · Ad·ver·bi·al · IPA /ædˈvɝbi.əl/ 01 a. Of or pertaining to an adverb; of the nature of an adverb; as, an adverbial phrase or form. 1. Of or pertaining to an adverb; of the nature of an adverb; as, an adverbial phrase or form.