警报器的英文是alarm。
详细释义：n，警报，警报器
例句：
The guard loosed the dogs when the burglar alarm went off.
防盗警报器一响，警卫就放出了警犬。
例句：
The night watch sounded the fire alarm.
守夜人弄响了火灾警报器。
闹钟 （= alarmclock）
例句：
his mouth gaping in a kind of rictus of startled alarm.
他的嘴张得有惊跳的闹钟那么大。
例句：
She set the alarm for 5 a.m.
她把闹钟拨到早晨五点响铃。
惊恐，忧虑，担心
例句：
She regarded her with a look of inscrutable alarm and terror.
她带着不可思议的惊讶和恐惧打量着她。
例句：
Companies such as Anglo-American viewed such debate with alarm.
像英美矿业公司这样的公司对这种讨论颇为惊慌。
v，警告
例句：
The sentry alarmed the sleeping men.
哨兵向熟睡的士兵报警。
例句：
The silence irritated and at the same time alarmed him.
沉默把他惹恼了，同时也使他警觉起来。
使惊恐，使忧虑，使担心
例句：
The fire alarmed the whole neighbourhood.
火灾使整个街坊邻里都惊恐起来。
例句：
They were alarmed by a sudden air attack.
突然空袭使他们大为惊恐。
挪威森林北辰星
