Stand by Definition 1 of 4Pro Tip 1/3Assistance Readiness Use 'stand by' to show your readiness to help immediately if needed. If the situation escalates, I’ll stand by for your signal. Pro Tip 2/3On Alert Conveys you are alert and waiting to act, similar to emergency services. Firefighters stand by, prepared for urgent calls. Pro Tip 3/3Support Signal Implies a ready position until a signal or event triggers action. Stand by until we confirm the system is operational.