from
The Collaborative International Dictionary of English v.0.48
Bluff \Bluff\, v. t. [imp. & p. p. {Bluffed}; p. pr. & vb. n.
{Bluffing}.]
1. (Poker) To deter (an opponent) from taking the risk of
betting on his hand of cards, as the bluffer does by
betting heavily on his own hand although it may be of less
value. [U. S.]
[1913 Webster]
2. To frighten or deter from accomplishing a purpose by
making a show of confidence in one's strength or
resources; as, he bluffed me off. [Colloq.]
[1913 Webster]