n.

1. a high steep bank (usually formed by river erosion)
2. pretense that your position is stronger than it really is
   
   • his bluff succeeded in getting him accepted
3. the act of bluffing in poker; deception by a false show of confidence in the strength of your cards;
   four flush

v.

1. deceive an opponent by a bold bet on an inferior hand with the result that the opponent withdraws a winning hand;
   bluff out
2. frighten someone by pretending to be stronger than one really is

adj.

1. very steep; having a prominent and almost vertical front;
   bold, sheer
   
   • a bluff headland
   • where the bold chalk cliffs of England rise
   • a sheer descent of rock
2. bluntly direct and outspoken but good-natured
   
   • a bluff but pleasant manner
   • a bluff and rugged natural leader