invisiblepen
nounUK /ɪnˈvɪzəbəl pɛn/
US /ɪnˈvɪzəbəl pɛn/
A pen that writes in a way you cannot see.
She used an invisiblepen to write a secret message to her friend.
OTHER MEANINGS
2. A pen whose ink only shows up under special light.
The detective shined a UV light on the note written with an invisiblepen.
3. A pretend pen used in games where kids write in the air.
During the game, he signed his name with an invisiblepen.
4. A digital pen that leaves no mark on the screen.
The tablet's invisiblepen lets you draw without leaving a trace.