Synonyms of bumbler
bunglerA bungler is a person who often fails to do things properly because they make mistakes or are clumsy.
• Why is this lying bungler still in the fire service?
duffer (informal)If you describe someone as a duffer, you mean that they are very bad at doing something.
• He was a duffer at cricket.
Thesaurus for bumbler from the Collins English Thesaurus