The term "storm-signal" refers to a warning sign or indication that a powerful weather system, such as a storm, is imminent. There are several synonyms for this term. One popular alternative is "weather warning," which is often used by meteorologists to alert the public of potentially dangerous weather conditions. Another synonym is "storm watch," which indicates that conditions are favorable for a storm to develop. "Advisory" is another term that can be used to describe a storm-signal, as it implies that caution should be exercised in the affected area. Other synonyms include "alert," "warning," and "signal" itself. Regardless of which term is used, it's important to heed all storm-related warnings and stay safe during severe weather events.