'half-spherical' originates from the combination of 'half' and 'spherical', where 'spherical' comes from the Latin word 'sphaericus', meaning 'pertaining to a sphere'.

'sphaericus' transformed into the Old French word 'spherique', and eventually became the modern English word 'spherical'.

Initially, it meant 'pertaining to a sphere', but over time it evolved to include 'half of a sphere' when combined with 'half'.