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flightless

American  
[flahyt-lis] / ˈflaɪt lɪs /

adjective

  1. incapable of flying.

    flightless birds such as the moa, rhea, and dodo.


flightless British  
/ ˈflaɪtlɪs /

adjective

  1. (of certain birds and insects) unable to fly See also ratite

"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 flightless

First recorded in 1870–75; flight 1 + -less

Explanation

Anything that's unable to propel itself through the air is flightless. You have at least one thing in common with a penguin: you're both flightless animals! The adjective flightless almost always describes birds that lost the ability to fly as they evolved, a group of about 60 species. When you imagine a flightless bird, you may picture the big, ungainly ones like emus and ostriches, but the tiny Inaccessible Island rail is also flightless. Wild turkeys can fly, but some turkeys, bred to be eaten on Thanksgiving, have bodies that are too wide and heavy for their wings to support them, and they've become flightless.

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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.

How oviraptors, bird-like but flightless dinosaurs, hatched their eggs has long been unclear.

From Science Daily • Mar. 19, 2026

Ski Dubai, an indoor ski resort in the Mall of the Emirates, offers an “ultimate penguin experience” where guests can feed its resident flightless birds, despite summertime temperatures outside that sometimes surpass 115 degrees Fahrenheit.

From The Wall Street Journal • Mar. 13, 2026

For a people nicknamed after a flightless bird, taking off overseas has somewhat ironically become a rite of passage for many New Zealanders.

From BBC • Mar. 2, 2026

A great horned owl found itself in a seriously sticky situation after becoming stuck in a glue trap in Orange County, rendering it both flightless and food-less.

From Los Angeles Times • Aug. 16, 2025

It also formerly had a 400-pound ostrichlike flightless bird, plus some impressively big reptiles, including a one-ton lizard, a giant python, and land-dwelling crocodiles.

From "Guns, Germs, and Steel: The Fates of Human Societies" by Jared M. Diamond