adverbial function
Definition - The role that adverbs play in a sentence, i.e. that of answering the questions how? , when?, where?, why?, and to what extent?.

1. The adverbial function is performed by by single adverbs, adverbial phrases, and adverbial clauses.

Example -
He ran slowly.

(In the above, the adverb slowly performs the adverbial function by answering the question How?)

Please comment