Adverb - Wikipedia
https://en.wikipedia.org/wiki/AdverbThe English word adverb derives (through French) from Latin adverbium, from ad- ("to"), verbum ("word", "verb"), and the nominal suffix -ium. The term implies that the principal function of adverbs is to act as modifiers of verbs or verb phrases. An adverb used in this way may provide information about the manner, place, time, frequency, certainty, or other circumstances of the activity denoted by the verb or verb phrase. Some examples:
Adverb Definition & Meaning - Merriam-Webster
www.merriam-webster.com › dictionary › adverbFull Definition of adverb. (Entry 1 of 2) : a word belonging to one of the major form classes in any of numerous languages, typically serving as a modifier of a verb, an adjective, another adverb, a preposition, a phrase, a clause, or a sentence, expressing some relation of manner or quality, place, time, degree, number, cause, opposition, affirmation, or denial, and in English also serving to connect and to express comment on clause content In "arrived early" the word "early" is an adverb