'full-size' originates from the combination of 'full' and 'size', where 'full' meant 'complete' and 'size' referred to 'dimensions or magnitude'.

'full-size' evolved from the Middle English word 'ful' and 'sise', eventually becoming the modern English term 'full-size'.

Initially, it meant 'complete dimensions', and this meaning has largely remained the same in modern usage.