butcher vs sad sack

butcher and sad sack both are nouns.

Word	Noun	Adjective	Verb	Adverb
butcher	Yes	No	Yes	No
sad sack	Yes	No	No	No

As nouns, butcher and sad sack are synonyms defined as:

butcher and sad sack: someone who makes mistakes because of incompetence

Other synonyms of butcher include blunderer, botcher, bumbler, bungler, fuckup, fumbler, stumbler.

butcher (noun)	sad sack (noun)
a person who slaughters or dresses meat for market	someone who makes mistakes because of incompetence
a brutal indiscriminate murderer
a retailer of meat
someone who makes mistakes because of incompetence

butcher (verb)	sad sack (verb)
kill (animals) usually for food consumption