To act in an inept, clumsy or inexpert manner; to make mistakes.
Spiders build webs and wait for insects to bumble into them.
To boom, as a bittern; to buzz, as a fly.
The act of one who bumbles; a mistake or error, especially through clumsiness.
Acting in a confused or ineffectual way; incompetent; showing little or no skill.
a bumbling fool