Source : Webster's Revised Unabridged Dictionary (1913)

Hobnob \Hob"nob`\, v. i. [imp. & p. p. {Hornobbed}; p. pr. & vb.
   n. {Hornobbing}.]
   1. To drink familiarly (with another). [ Written also
      {hob-a-nob}.]

   2. To associate familiarly; to be on intimate terms.