1. Any nonverbal action or gesture that encodes a message
   "The secret agent used subtle hand signalling to communicate with his partner across the room";
   - signal, signaling [N. Amer], sign
    
2. (rail system) the signals and associated cabling and equipment
   "The railway company upgraded its signalling system to improve safety";
   - signaling [N. Amer]

1. Communicate silently and non-verbally by signals or signs
   "The hikers signald their location to the rescue helicopter";
   - 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
    
3. Show intention to turn or change lanes while driving, typically using turn signals
   "Always signal before changing lanes";
   - indicate [Brit]

Derived forms: signallings

Type of: communicate, communication, intercommunicate, tell

Encyclopedia: Signalling