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careless; thoughtless; hasty; rash
彼女はそそっかしくてよく物を落とす。
She is careless and often drops things.
そそっかしい性格で忘れ物が多いんです。
Because of my hasty personality, I forget things a lot.
そそっかしくて大事な書類を間違えてしまった。
I was careless and made a mistake with important documents.