flightless

American  

[flahyt-lis] / ˈflaɪt lɪs /

adjective

1. incapable of flying.

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

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flightless British  

/ ˈflaɪtlɪs /

adjective

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

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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.

Example Sentences

A one-eyed flightless African Grey parrot has been given a specially-adapted aviary to help her thrive.

From BBC • Dec. 9, 2025

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

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

From Slate • Aug. 8, 2025

In other findings, the study concluded more than 87% were endemic to islands; nearly two-thirds inhabited forests; 45% ate primarily insects and other invertebrates; and 20% were completely or partially flightless.

From Science Daily • Nov. 27, 2024

She knew the Latin phrase “tempus fugit,” which means “time flies,” like a bird—but there were flightless birds, after all: ostriches and emus and dodos and so on.

From "The Interrupted Tale" by Maryrose Wood