| 释义 |
secret ink
noun
: a fluid for invisible writing to be made visible afterwards: as
a. : a colorless plant juice that can be made visible by subjecting to heat
b. : one of a pair of water solutions of chemicals that are colorless or nearly so and that when combined form a strongly colored compound
c. : a water solution of a fluorescent substance that is colorless in visible light but leaves characters on paper that fluoresce when exposed to ultraviolet light |