Choose the correct meaning of the following idiom from the options given below:-

'To meet one's waterloo'

To experience a decisive or final defeat

The correct answer is Option (3) → To experience a decisive or final defeat

The idiom refers to the Battle of Waterloo (1815), where Napoleon Bonaparte was decisively and finally defeated by the forces of the Seventh Coalition, ending his reign as Emperor.

Therefore: To meet one's Waterloo means to encounter the ultimate, decisive challenge or opponent that leads to one's downfall or permanent defeat.