'half-sphere' originates from the combination of 'half' and 'sphere', where 'half' means 'one of two equal parts' and 'sphere' means 'a round solid figure'.

The term 'half-sphere' evolved from the combination of the Old English word 'healf' and the Greek word 'sphaira', eventually forming the modern English term 'half-sphere'.

Initially, it meant 'half of a round solid figure', and this meaning has largely remained the same in modern usage.