'braincase' originates from Middle English, combining 'brain' from Old English 'brægen' meaning 'brain' and 'case' from Latin 'capsa' meaning 'box or container'.

'brægen' and 'capsa' combined in Middle English to form 'braincase', eventually becoming the modern English word 'braincase'.

Initially, it meant 'a container for the brain', and this meaning has largely remained the same in modern usage.