Bluff

Etymology

From Dutch "bluffen" (to brag, boast), which entered American English through the card game later called poker, where a "bluff" is a bet made on a weak hand.

This is unrelated to the other "bluff," meaning a steep cliff — from a nautical adjective "bluff," broad and steep-fronted.

noun · /bluff/
An attempt to deceive by projecting more confidence, strength, or intention than one actually has.
What it names
A specific deception — false show meant to be tested or not — central to poker, negotiation, and diplomacy.
Example
His threat to walk away was a bluff, and the moment they called it, the deal closed on their terms.
Related idea
A bluff is a performance of strength you may not have to back up; a lie is a false assertion of fact — a bluff invites the other side to test it, where a lie hopes they never do.
noun · /bluff/
A broad, steep cliff or headland, especially one overlooking a river, lake, or sea.
What it names
a high, steep bank or promontory
Example
The old town sat on a bluff high above the Mississippi.
Related idea
Communities perched on eroding bluffs are among the first to face managed retreat as the water gnaws the land away.