noun
rash act; unreasonable action; indiscretion
Formal or literary term for acting without due consideration; implies a lack of judgment or discrimination. Rare in everyday speech.
彼の妄挙が会社に大きな損害を与えた。
His rash actions caused great damage to the company.
妄挙を慎むようにと上司に注意された。
My boss warned me to refrain from reckless behavior.
Compound of 妄 (reckless, deluded) and 挙 (action, undertaking). The exact historical origin is uncertain, but it follows classical Chinese word formation patterns.