'breakthrough' originates from Old English components: specifically the words 'brecan' and 'þurh', where 'brecan' meant 'to break' and 'þurh' meant 'through'.

'breakthrough' developed from the verbal phrase 'break through' in earlier English and was established as the single-word noun 'breakthrough' in later Modern English usage (19th century onward).

Initially, it meant 'the act of breaking through (a physical barrier)'; over time it evolved to mean 'a major discovery or significant advance' in scientific, technical, or figurative contexts.