The word 警报 is formed by combining two meaningful characters: 警, which conveys the idea of alertness, vigilance, or a warning, and 报, which means to report or announce. Together, they create a compound concept that functions as a single unit meaning "alarm", picturing the mechanism of a warning that is reported, such as a siren or alert signal, where the first character provides the nature (a caution) and the second provides the action (disseminating it).