Webster's Revised Unabridged Dictionary · 1913

Bluff

Bluff ({not transcribed}) , adjective

[Compare OD. blaf flat, broad, blaffaert one with a broad face, also, a boaster; or German verbluffen to confuse, LG. bluffen to frighten; to unknown origin.]

1.
Having a broad, flattened front; as, the bluff bows of a ship.
Bluff visages. — Irving
2.
Rising steeply with a flat or rounded front.
A bluff or bold shore. — Falconer
Its banks, if not really steep, had a bluff and precipitous aspect. — Judd
3.
Surly; churlish; gruff; rough.
4.
Abrupt; roughly frank; unceremonious; blunt; brusque; as, a bluff answer; a bluff manner of talking; a bluff sea captain.
Bluff King Hal. — Sir W. Scott
There is indeed a bluff pertinacity which is a proper defense in a moment of surprise. — I. Taylor

Bluff , noun

1.
A high, steep bank, as by a river or the sea, or beside a ravine or plain; a cliff with a broad face.
Beach, bluff, and wave, adieu. — Whittier
2.
An act of bluffing; an expression of self-confidence for the purpose of intimidation; braggadocio; as, that is only bluff, or a bluff.
3.
A game at cards; poker. [United States] — Bartlett

Bluff ({not transcribed}) , transitive verb

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. [United States]
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. [Colloquial]

Bluff , intransitive verb

To act as in the game of bluff.