Imprudent (adjective)

1. Not showing good judgment or caution; not wise.
2. Not careful or discreet in one's actions or words.
3. Not marked by or given to careful consideration.

Origin:

From the latin in- (not) + prudentem (prudent), from the verb prudere (to be wise).

Examples:

1. It was imprudent of him to invest all his savings in a high-risk stock.
2. Her imprudent behavior led to her dismissal from the company.
3. The imprudent decision to cut corners on safety procedures led to the accident.
4. His imprudent remarks caused him to lose credibility.
5. The imprudent use of credit led to financial ruin.