From The Collaborative International Dictionary of English v.0.48 :
Signal \Sig"nal\, v. t. [imp. & p. p. Signaled or Signalled; p. pr. & vb. n. Signaling or Signalling.] 1. To communicate by signals; as, to signal orders. [1913 Webster] 2. To notify by a signals; to make a signal or signals to; as, to signal a fleet to anchor. --M. Arnold. [1913 Webster]From WordNet (r) 3.0 (2006) :
signaling n 1: any nonverbal action or gesture that encodes a message; "signals from the boat suddenly stopped" [syn: signal, signaling, sign]