KO punch vs Sunday punch

KO punch and Sunday punch both are nouns.

Word	Noun	Adjective	Verb	Adverb
KO punch	Yes	No	No	No
Sunday punch	Yes	No	No	No

As nouns, KO punch and Sunday punch are synonyms defined as:

KO punch and Sunday punch: a hard punch that renders the opponent unable to continue boxing

Other synonyms of KO punch include haymaker, knockout punch.

KO punch (noun)	Sunday punch (noun)
a hard punch that renders the opponent unable to continue boxing	a hard punch that renders the opponent unable to continue boxing