The Collaborative International Dictionary of English v.0.48:

Overlade \O`ver*lade"\, v. t. [imp. Overladed; p. p.
   Overladen; p. pr. & vb. n. Overlading.] [Cf. Overload.]
   To load with too great a cargo; to overburden; to overload.
   --Spenser.
   [1913 Webster]