Source : Webster's Revised Unabridged Dictionary (1913)

Halloo \Hal*loo"\, v. i. [imp. & p. p. {Hallooed}; p. pr. & vb.
   n. {Halloing}.]
   To cry out; to exclaim with a loud voice; to call to a
   person, as by the word halloo.

         Country folks hallooed and hooted after me. --Sir P.
                                                  Sidney.