adverbial

from WordNet (r) 3.0 (2006)

adverbial
    adj 1: of or relating to or functioning as an adverb; "adverbial
           syntax"
    n 1: a word or group of words function as an adverb

from The Collaborative International Dictionary of English v.0.48

Adverbial \Ad*ver"bi*al\, a. [L. adverbialis: cf. F. adverbial.]
   Of or pertaining to an adverb; of the nature of an adverb;
   as, an adverbial phrase or form.
   [1913 Webster]