基本解释adj.预先警戒的；预防的；留心的同根派生 英汉例句用作形容词 (adj.)He thrusts aside all precautionary advice.他把一切警告都置之一边。We have to take precautionary measures.我们不得不采取预防措施。This was purely precautionary with all three players.这完全是对三名球员的预防措施。