noun

A word or phrase functioning as a major clause constituent and typically expressing place (in the garden), time (in May), or manner (in a strange way).

Adverbials that modify the sentence as a whole are sentence adverbials, and adverbs that function as sentence adverbials are sentence adverbs.

adjective

Relating to or functioning as an adverb or adverbial.

Such adverbs are sometimes called prepositional adverbs, sometimes adverbial particles.