blaf

The English word 'bluff' in all three of its main senses — the geographical feature (a high, steep cliff or promontory with a broad face), the adjective meaning frank and direct, and the verb meaning to deceive through false confidence — derives ultimately from Dutch or Low German roots connected to the idea of a broad, flat front. The nautical ancestor is Dutch blaf or bluff, used to describe the broad, flat bow of a ship — a hull design that presented a wide, flat face to the water rather than a sharp, narrow prow. From this ship-bow sense, the word extended to coastal cliffs and headlands that presented a similar broad, flat face to the sea.

The geographical sense of 'bluff' — a high bank or cliff with a broad, steep face — entered English in the seventeenth century, particularly in American English, where it described the characteristic steep banks above rivers and lakes in the interior of the continent. When European explorers and settlers moved through the Mississippi River valley and the Great Plains, 'bluff' became a standard term for the dramatic earthen or sandstone cliffs along river banks — features that appear throughout the names of American towns (Council Bluffs, Iowa; Red Bluff, California). The word came into American usage early and broadly.

The poker sense — to bluff, meaning to bet or act with false confidence to mislead opponents about the strength of one's hand — appears in American English in the mid-nineteenth century. The connection between the nautical 'broad flat front' and the deceptive act may run through the idea of presenting a bold, unreadable face: the bluff bow of a ship gives away nothing about what lies behind it; the bluffing poker player presents a flat, confident front that conceals a weak hand. The transition from physical description to psychological strategy is one of the most interesting shifts in the word's history.

The adjective 'bluff' — meaning frank, direct, good-naturedly brusque — may derive separately from a Flemish or Dutch word for 'blustering,' though it was likely reinforced by the same broad-front imagery: a bluff person, like a bluff headland, presents their face directly, without concealment or subtlety. The three senses of 'bluff' — landscape, deception, frankness — all touch the same original Dutch shape-word at different angles.