'Hereby' definitions:

Definition of 'hereby'

(from WordNet)
adverb
(formal) by means of this; "I hereby declare you man and wife" [syn: hereby, herewith]

Definition of 'Hereby'

From: GCIDE
  • Hereby \Here*by"\, adv.
  • 1. By means of this. [1913 Webster]
  • And hereby we do know that we know him. --1 John ii. 3. [1913 Webster]
  • 2. Close by; very near. [Obs.] --Shak. [1913 Webster]