a. Weak or insubstantial; flimsy: a tenuous argument; a tenuous link between pieces of evidence.
b. Precarious or insecure: tenuous survival.
2. Long and thin; slender: tenuous strands.
3. Having a thin consistency: Pluto's tenuous envelope of gas.
[Latin tenuis; see ten- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 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.