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Synonyms

loopy

American  
[loo-pee] / ˈlu pi /

adjective

loopier, loopiest

  1. full of loops.

  2. Slang.

    1. eccentric; crazy; dotty.

    2. befuddled or confused, especially due to intoxication.

  3. Scot. crafty; sly.

loopy British  
/ ˈluːpɪ /

adjective

  1. full of loops; curly or twisted

  2. informal slightly mad, crazy, or stupid

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of loopy

First recorded in 1815–25; loop 1 + -y 1

Explanation

Someone who's loopy is batty or nutty — in other words, not the picture of mental health. You might get so tired after staying up late to study for a test that you start to act goofy and giggly and a little bit loopy. Even if you are completely sane, you can still act loopy when you're embarrassed or tired or just being silly. You might love the circus because of the loopy music and the painted-on, loopy smiles of the clowns. Or maybe you're a fan of loopy comedies, films that feature characters with harebrained ideas that backfire in ridiculous ways. This informal meaning dates from the early 20th century — earlier, the word meant "deceitful."

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Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Appeared in the January 16, 2026, print edition as 'A Lively, Loopy Zombie Movie'.

From The Wall Street Journal • Jan. 15, 2026

Loopy, long second serves are followed by 704th-ranked Anderson casually batting easy returns into the net.

From BBC • Jan. 13, 2026

Loopy Products makes products from upcycled agricultural waste; their sustainable coffee mug, made with waste from coffee manufacturing, was a Global Innovation Award Finalist at the Inspired Home Show this year.

From Washington Times • May 9, 2023

Loopy, winding, and heavily atmospheric, this tropical noir finds just the right balance between social critique and Lynchian dreaminess.

From Slate • Aug. 22, 2019

Loopy and lopsided stars that look like I did them.

From "Sunny" by Jason Reynolds

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.