nieprzewidujący 英語で:

Because of his impetuous character, he sometimes makes decisions dictated by emotions.

an impetuous outburst

An impetuous man. An impetuous decision.

He was high-spirited and impetuous.

Her friends seem to avoid her, as her impetuous and impulsive behavior began to get her into a lot of trouble.

Not sparring today? -Advanced practice. Pam, a bit beyond a girl like you who's ... kind of impetuous...

Your impetuous remarks about us seem to have rung down the curtain on our good relationship.