as in, enclosed in four walls;
defined by its lines and conventions.
as in, a public space at the center of civilization;
site of assembly, spectacle, encounter and execution.
as in, I’m being square, I’m telling it like it is, whether you like it or not.
as in, you’re a square, you’re backward, behind in the times, a stick in the mud.
as in, we’re square, we’re even, we owe nothing to each other.