1. Not spoken: indicated tacit approval by smiling and winking.
2. Implied by or inferred from actions or statements: Management has given its tacit approval to the plan.
3. Archaic Not speaking; silent.
[Latin tacitus, silent, past participle of tacēre, to be silent.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.