adj. dens·er, dens·est
a. Having relatively high density.
b. Crowded closely together; compact: a dense population.
2. Hard to penetrate; thick: a dense jungle.
a. Permitting little light to pass through, because of compactness of matter: dense glass; a dense fog.
b. Opaque, with good contrast between light and dark areas. Used of a photographic negative.
4. Difficult to understand because of complexity or obscurity: a dense novel.
5. Slow to apprehend; thickheaded.
[Middle English, from Latin dēnsus.]
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.