1. Having no legal force; invalid: render a contract null and void.
2. Of no consequence, effect, or value; insignificant.
3. Amounting to nothing; absent or nonexistent: a null result.
4. Mathematics Of or relating to a set having no members or to zero magnitude.
tr.v. nulled, null·ing, nulls
To make null.
1. Zero; nothing.
2. An instrument reading of zero.
[French nul, from Old French, from Latin nūllus; see ne in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. 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.