Source : Webster's Revised Unabridged Dictionary (1913)

Overdose \O`ver*dose"\, v. t.
   To dose to excess; to give an overdose, or too many doses,
   to.

Overdose \O"ver*dose`\, n.
   Too great a dose; an excessive dose.

Source : WordNet®

overdose
     v : dose too heavily; "The rock star overdosed and was found
         dead in his hotel room" [syn: {o.d.}]