Sunday punch

noun

1. Boxing. the most powerful and effective punch of a boxer, especially the punch used in trying to gain a knockout.
2. anything, as an armed force, line of argument, etc., capable of inflicting a powerful blow on a hostile or opposing person or thing.

Sunday punch

noun

1. boxing a heavy blow intended to knock out one's opponent
2. any manoeuvre or action intended to crush an opponent

Word History and Origins

Origin of Sunday punch¹

First recorded in 1930–35