This adjective describes something prone to fall, unstable, or dangerous—a precarious situation or hazardous condition. In Acts 27:9, sailing has become dangerous because the season is advancing toward winter storms. Classical usage applied this to anything unstable: precarious political positions, unreliable things, dangerous illnesses, dubious propositions. The multilingual evidence is remarkably uniform: dangerous, peligrosa, dangereux—showing universal recognition of risk and hazard. The medical usage for dangerous diseases suggests life-threatening conditions, which fits Paul's voyage narrative where lives are indeed at stake.