stu·pid (stpĭd, sty-)
adj. stu·pid·er, stu·pid·est
1. Slow to learn or understand; obtuse.
2. Tending to make poor decisions or careless mistakes.
3. Marked by a lack of intelligence or care; foolish or careless: a stupid mistake.
4. Dazed, stunned, or stupefied: felt stupid after taking the pain medication.
5. Used to express disparagement or exasperation: Take your stupid notebook and go home.
A stupid or foolish person.
[Latin stupidus, from stupēre, to be stunned.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 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.