Nash Equilibrium
Etymology
Named for mathematician John Nash, who proved its existence in a 1950 paper; the concept and name are eponymous, cemented by his 1994 Nobel and later biography. “Equilibrium” is from Latin “aequilibrium,” from “aequus,” equal, and “libra,” balance — a state where opposing forces hold steady.
noun phrase · /NASH ee-kwih-LIB-ree-um/
A stable outcome in a strategic situation where no player can do better by changing their move while everyone else keeps theirs.
What it names
A precise tool for spotting where a competitive situation settles — the point everyone locks into, even when it is collectively bad, because no one gains by moving alone.
Example
Everyone works late because slacking looks bad — a miserable Nash equilibrium no one can escape alone.
Related idea
A Schelling point is the outcome people converge on through shared expectation without communicating; a Nash equilibrium is defined by no one wanting to deviate, whether or not it is the obvious focal choice.