at a signal

Examples (10)

• At a prearranged signal, everyone started cheering.
• The doors will open at a given signal from the security guard.
• The runners took off at a sharp signal from the starting pistol.
• She knew to leave at a subtle signal from her host.
• The emergency crew responded immediately at a distress signal.
• All participants must halt at a clear signal from the instructor.
• The robot performs its task at a specific signal from the remote control.
• The audience applauded at a silent signal from the master of ceremonies.
• He will only speak at a discreet signal from his lawyer.
• The train departed at a whistle signal from the platform attendant.