Source : Webster's Revised Unabridged Dictionary (1913)

Overload \O`ver*load"\, v. t. [imp. & p. p. {Overloaded}; p. pr.
   & vb. n. {Overloading}.] [Cf. {Overlade}.]
   To load or fill to excess; to load too heavily.

Overload \O"ver*load`\, n.
   An excessive load; the excess beyond a proper load.

Source : WordNet®

overload
     n 1: an electrical load that exceeds the available electrical
          power
     2: an excessive burden [syn: {overburden}]
     v 1: become overloaded; "The aerator overloaded"
     2: fill to excess so that function is impaired; "Fear clogged
        her mind"; "The story was clogged with too many details"
        [syn: {clog}]
     3: place too much a load on; "don't overload the car" [syn: {surcharge},
         {overcharge}]