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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.

See Examples For:

But outside scientists suggest it’s a stretch to see that as a major step toward resurrecting the moa, a giant flightless bird that disappeared from its New Zealand habitat in the 1400s.

From Los Angeles Times May 21, 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

This animal, the flightless and tree-climbing lagerpetid, was first identified by scientists in 2016 and lived during the Triassic period between 242 and 212 million years ago.

From Science Daily Dec. 9, 2025

Before humans, flightless birds like the kākāpō and kiwi thrived.

From Slate Aug. 8, 2025

He had spent most of his years alone and trapped by his flightless body.

From "Where the Mountain Meets the Moon" by Grace Lin

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