sad sack

Từ điển WordNet v3.1 - WordNet Dictionary

noun

someone who makes mistakes because of incompetence
• Syn:
bungler, blunderer, fumbler, bumbler, stumbler,
botcher, butcher, fuckup
• Derivationally related forms:
butcherly (for: butcher), botch (for: botcher), stumble (for: stumbler), bumble (for: bumbler), fumble (for: fumbler), blunder (for: blunderer), bungle (for: bungler)
• Hypernyms:
incompetent, incompetent person