Source : Webster's Revised Unabridged Dictionary (1913)

Loggerheaded \Log"ger*head`ed\, a.
   Dull; stupid. --Shak.

         A rabble of loggerheaded physicians.     --Urquhart.

Source : WordNet®

loggerheaded
     adj : used informally [syn: {blockheaded}, {boneheaded}, {fatheaded},
            {thick}, {thickheaded}, {thick-skulled}, {wooden-headed}]