警けい報ほう器きけいほうきCommon word›Meanings1nounalarm; alarm device; sensorA device that detects danger, intrusion, fire, train crossings, etc. and gives a warning sound or signal. 警報器 emphasizes a device/detector, while 警報機 is also used for larger alarm mechanisms.火か災さい警けい報ほう器きが突