'full-spherical' originates from the combination of 'full' and 'spherical', where 'full' means 'complete' and 'spherical' means 'having the shape of a sphere'.

The term 'spherical' comes from the Latin word 'sphaericus', which was derived from the Greek word 'sphaira', meaning 'globe' or 'ball'.

Initially, 'spherical' referred to anything round or ball-like, and 'full' was added to emphasize completeness.