Adverb Definition

ădvûrb

adverbs

noun

The part of speech that modifies a verb, an adjective, another adverb, or an entire clause or sentence.

American Heritage

Any of a class of words used generally to modify a verb, an adjective, another adverb, a phrase, or a clause, by expressing time, place, manner, degree, cause, etc.: English adverbs often end in -ly (Ex.: fast, carefully, then)

Webster's New World

Any of the words belonging to this part of speech, such as so, very, and rapidly.

American Heritage

(grammar) A word that modifies a verb, adjective, other adverbs, or various other types of words, phrases, or clauses.

Wiktionary

Synonyms:

Synonyms:
intensive
intensifier
adverbial modifier
modifier
qualifier
qualifying construction
adverbial
limiting word

Other Word Forms of Adverb

Noun

Singular:

adverb

Plural:

adverbs

Origin of Adverb

Middle English adverbe from Old French from Latin adverbium (translation of Greek epirrhēma) ad- in relation to ad– verbum word, verb wer-⁵ in Indo-European roots

From American Heritage Dictionary of the English Language, 5th Edition
From French adverbe, from Latin adverbium, from ad- (“to”) + verbum (“word”).

From Wiktionary