保持警惕;提高戒备,随时准备应对危险、欺骗或突发情况。(也常见变体:be on your guard)
/bi ɑn ɡɑrd/
Please be on guard when you cross the street at night.
晚上过马路时请保持警惕。
In a market full of rumors and half-truths, investors must be on guard against promises that sound too good to be true.
在一个充满谣言与半真半假的市场里,投资者必须对那些“好得不真实”的承诺保持警惕。
guard 来自古法语 garde(“看守、防卫”),进一步可追溯到日耳曼语族中“守护、警戒”的词根;be on guard 字面意思是“处在守卫/警戒状态”,最初常用于军事或站岗语境,后来引申为日常生活中的“防范、提防”。