openingsignal
nounUK /ˈəʊpənɪŋ ˈsɪɡnəl/
US /ˈoʊpənɪŋ ˈsɪɡnəl/
A sign that tells you it is time to start.
The bell was the opening signal for the race to begin.
OTHER MEANINGS
2. A sound or light that shows a game or show is about to begin.
The lights dimmed as the opening signal for the play.
3. A first message that starts a conversation or exchange.
Her smile was the opening signal for us to say hello.
4. A radio or electronic pulse that starts a device working.
The opening signal woke up the machine.