'late-stage' originates from the combination of 'late' and 'stage', where 'late' means 'occurring near the end' and 'stage' refers to 'a specific point in a process'.

'late' and 'stage' have been used in English since the Middle Ages, and their combination into 'late-stage' reflects modern usage to describe the final phases of processes.

Initially, 'late' and 'stage' were used separately, but their combination into 'late-stage' has come to specifically denote the final phases of processes or developments.