The international radiotelephony distress signal indicating grave, imminent danger

• Used by aircraft and vessels; spoken three times to declare emergency

国际无线电话遇险呼叫，表示严重且迫在眉睫的危险

• 由飞机和船舶使用；连续呼叫三次以宣告紧急情况

A figurative cry for urgent help or rescue

• Any urgent alert signaling a crisis

引申义：紧急求助的呼喊或援助请求

• 指任何表明危机的紧急警报