An individual with few redeeming characteristics. Stems from the fact that spheres appear exactly the same when viewed from any perspective. The phrase is commonly attributed to astronomer Fritz Zwicky.

A real prick

Someone who's a perfectly smooth bastard no matter which way you look at him.

Also works with Spherical nutjob, spherical jackass.

Syntax: Spherical cuss-word

History: Often attributed to the eccentric Swiss Astronomer Fritz Zwicky, who used to refer to fellow astronomers at the Mt. Wilson Observatory as Spherical Bastards. "Because", in his words, "they were bastards, when looked at from any side".

Source: dynamical-systems.org/zwicky/Zwicky-e.html