secret ink

noun

: a fluid for invisible writing to be made visible afterwards: such 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

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

  • More than 250,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

Dictionary Entries Near secret ink

Cite this Entry

“Secret ink.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/secret%20ink. Accessed 22 Jun. 2024.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!