haymaker vs knockout punch

haymaker and knockout punch both are nouns.

Word	Noun	Adjective	Verb	Adverb
haymaker	Yes	No	No	No
knockout punch	Yes	No	No	No

As nouns, haymaker and knockout punch are synonyms defined as:

haymaker and knockout punch: a hard punch that renders the opponent unable to continue boxing

Other synonyms of haymaker include KO punch, Sunday punch.

haymaker (noun)	knockout punch (noun)
a hard punch that renders the opponent unable to continue boxing	a hard punch that renders the opponent unable to continue boxing
a farm machine that treats hay to cause more rapid and even drying