privatesignal
nounUK /ˈpraɪvət ˈsɪɡnəl/
US /ˈpraɪvət ˈsɪɡnəl/
A private signal is a secret sign that only certain people know and understand.
The club members used a private signal, like a special handshake, to greet each other.
OTHER MEANINGS
2. A signal sent in a way that keeps it hidden from others.
The spy sent a private signal with a tiny flashlight.
3. A personal sign that shows how someone feels without words.
Her smile was a private signal that she was happy.
4. A special sound or light used only by a certain group.
The ship used a private signal to talk to its own crew.