If you describe a person as level-headed, you mean that they are calm and sensible even in difficult situations.
例句
Simon is level-headed and practical...西蒙为人头脑冷静，讲求实际。His level-headed approach suggests he will do what is necessary.他这人沉稳冷静，会见机行事的。
英英词典释义
Adjective
1. exercising or showing good judgment;
"healthy scepticism""a healthy fear of rattlesnakes""the healthy attitude of French laws""healthy relations between labor and management""an intelligent solution""a sound approach to the problem""sound advice""no sound explanation for his decision"