safeguard

1. V-T To safeguard something or someone means to protect them from being harmed, lost, or badly treated. 保护; 保卫[正式]

They will press for international action to safeguard the ozone layer. 他们将竭力要求国际行动来保护臭氧层。

2. N-COUNT A safeguard is a law, rule, or measure intended to prevent someone or something from being harmed. 安全条例; 防护措施

As an additional safeguard against weeds you can always use an underlay of heavy duty polyethylene. 作为另外一种预防杂草的防护措施，你可以一直使用一层厚重耐磨的聚乙烯底垫。