Prepositional adverb

/pɹˌɛpəzˈɪʃənəl ˈadvɜːb/

/pɹˌɛpəzˈɪʃənəl ˈædvɜːb/

an adverb that is formed by adding a preposition to an adjective or adverb, creating a new word that functions as an adverbial phrase