Give or constitute a signal, not necessarily verbally(verb)
WordNet. Princeton University. 2010.
Use "send a message" in a sentence
"If they could reach the Merchant Spacefleet Union, he could send a message from there to Starbase 37, and have them warn the Enterprise."
"In a sitting with Leonard, December 1917, the young man, whose nickname was Bim, appeared to communicate through Feda to members of his family: Bim now wants to send a message to his Father."
"Faxing is one of the most forceful ways you can send a message today."