'two-class' originates from English, combining the numeral 'two' (from Old English 'twā') and the noun 'class' which comes from Latin 'classis' via Old French 'classe'.

'class' changed from Latin word 'classis' into Old French 'classe' and entered Middle English as 'classe'/'class', and the compound formation with numerals (e.g. 'two-class') developed in modern English.

Initially, 'class' meant 'a division or group' in Latin and early English; over time, compounds like 'two-class' have retained the core sense of 'divided into two groups'.