VERB (2)

1. bid over an opponent's bid when one's partner has not bid or doubled;

2. bid higher than others;

The Collaborative International Dictionary of English v.0.48:

Outbid \Out*bid"\, v. t. [imp. Outbid or Outbade (?); p. p.
   Outbid or Outbidden (?); p. pr. & vb. n. Outbidding.]
   To exceed or surpass in bidding; to bid a higher price.
   [1913 Webster]

         Prevent the greedy, and outbid the bold. --Pope.
   [1913 Webster]