The Collaborative International Dictionary of English v.0.48:

Abuzz \A*buzz"\, a. [Pref. a- + buzz.]
   In a buzz; buzzing. [Colloq.] --Dickens.
   [1913 Webster]

WordNet (r) 3.0 (2006):

abuzz
    adj 1: noisy like the sound of a bee; "the room was abuzz over
           the latest scandal" [syn: abuzz, buzzing]