invisible ink
"Invisible ink" has been used historically for secret communication, revealing hidden messages when treated with heat, chemicals, or other methods.
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Definition
B2Security
(technical)A fluid used to write hidden messages that become visible when exposed to heat, chemicals, or other methods.
Example
- Spies often used invisible ink to send secret messages during wartime.
- The letter appeared blank until it was held over a candle flame, revealing the hidden text.
B1Entertainment
(informal, pranks)A fluid that initially appears visible but disappears shortly after, often used for jokes.
Example
- He wrote a funny message with invisible ink that vanished after a few minutes.
- The children giggled as their drawings made with invisible ink disappeared.
Similar
Terms that have similar or relatively close meanings to "invisible ink":