na-adjective, noun
clumsiness; stupidity; blunder
Rare, old-fashioned word for a foolish mistake or clumsiness. Modern Japanese more often uses へま or ドジ.
そんなぶまをやらかすなんて、らしくないよ。
It's not like you to make such a stupid blunder.
The historical derivation is uncertain; the kanji 不間 literally suggest 'not interval' but the connection to the meaning is unclear.