I know that words can have their etymology independent of words that share the same spelling, but according to Etymology Dictionary, both the geophysical "Bluff" and the deceptive "Bluff" originate in the Dutch language. But... what is the linguistic connection between them?
The first usage is the geophysical bluff:
"broad, vertical cliff," 1680s, from bluff (adj.) "with a broad, flat front" (1620s), a sailors' word, probably from Dutch blaf "flat, broad." Apparently a North Sea nautical term for ships with flat vertical bows, later extended to landscape features
The deceptive bluff: seems to relate to poker and bragging.
How do cliffs & the action of deceiving relate? Is it because they are both dangerous/risky? Or that a lie is as big as a mount?
Do we know the semantic drift and the historical relationship?