Source : Webster's Revised Unabridged Dictionary (1913)

Overhear \O`ver*hear"\, v. t. [imp. & p. p. {Overheard}; p. pr.
   & vb. n. {Overhearing}.] [AS. oferhi['e]ran.]
   1. To hear more of (anything) than was intended to be heard;
      to hear by accident or artifice. --Shak.

   2. To hear again. --ShaK.

Source : WordNet®

overhear
     v : hear, usually without the knowledge of the speakers; "We
         overheard the conversation at the next table" [syn: {catch},
          {take in}]
     [also: {overheard}]