adj. loop·i·er, loop·i·est
1. Consisting of or having many loops: loopy handwriting.
2. Crazy or eccentric: "March was the month when most people went loopy, like the March hares" (Edna O'Brien).
3. Offbeat or bizarre: "the loopy energy of Harpo Marx" (Michael Wood).
4. Befuddled or disoriented: felt loopy from dehydration.
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.