A person who performs tasks clumsily, ineptly, or badly; someone who makes mistakes through carelessness or lack of skill.
From 'bungle' (to perform clumsily, likely from Scandinavian 'bung' meaning to beat or strike) plus agentive suffix '-er', creating a noun for someone who bundles things badly.
The word 'bungler' has an interesting psychology—we use it for people who try but fail, not for people who refuse to try, suggesting we recognize effort even when results are bad.
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