'first-class' originates from the English words 'first' and 'class', where 'first' meant 'foremost in position' and 'class' referred to a 'category or rank'.

'first-class' evolved from the combination of 'first' and 'class' in the 19th century to describe superior quality or service.

Initially, it meant 'of the highest rank or quality', and this meaning has largely remained the same in modern usage.