lightmessage
nounUK /ˈlaɪtˌmɛsɪdʒ/
US /ˈlaɪtˌmɛsɪdʒ/
A lightmessage is a short note sent quickly to someone using light.
She sent a lightmessage to her friend across the dark yard with a flashlight.
OTHER MEANINGS
2. A brief signal made with a lamp or flashlight.
The sailor gave a lightmessage to the other boat.
3. A very short, bright digital message that pops up on a screen.
A lightmessage appeared on his watch to remind him to drink water.
4. A friendly greeting sent by shining a light.
They shared a lightmessage from window to window before bed.