Source : Webster's Revised Unabridged Dictionary (1913)

Overbid \O`ver*bid"\, v. t.
   To bid or offer beyond, or in excess of. --Dryden.

Source : WordNet®

overbid
     n 1: a bid that is higher than preceding bids
     2: (bridge) a bid that is higher than your opponent's bid
        (especially when your partner has not bid at all and your
        bid exceeds the value of your hand) [syn: {overcall}]
     v 1: to bid for more tricks than one can expect to win,
     2: bid more than the object is worth [ant: {underbid}]
     [also: {overbidding}, {overbidden}]