n. The use of signals; in railroading, the business of controlling the traffic by means of signals.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. any nonverbal action or gesture that encodes a message
Word Usage
"PARIS — WPP PLC, the world's largest marketing company by revenue, joined peers in signaling a recovery in the advertising industry by saying Friday that third-quarter sales rose 12%."