(in modal logic) a semantic device formalizing the notion of what the world might have been like. A statement is necessarily true if and only if it is true in every possible world
Examples of 'possible world' in a sentence
possible world
There cannot even be two indiscernible individuals each belonging to a distinct possible world.
The Times Literary Supplement (2015)
Not only numerically distinct but intrinsically perfectly similar individuals are not possible in the same possible world.