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1. Any nonverbal action or gesture that encodes a message
   - signal, sign, signalling

1. Communicate silently and non-verbally by signals or signs
   - sign, signalize, signalise [Brit]
    
2. Be a signal for or a symptom of
   "The economic indicators signal that the euro is undervalued";
   - bespeak, betoken [archaic], indicate, point

Type of: communicate, communication, intercommunicate, tell

Encyclopedia: Signaling Signaling, Semaphore procedure