From Longman Dictionary of Contemporary Englishflightlessflight‧less /ˈflaɪtləs/ adjective HBunable to fly a flightless bird
Examples from the Corpus
flightless• There is a certain wasp, for example, of which the female is flightless.• This huge flightless bird has regularly appeared in illustrated fossil books as a giant carnivore.• If these huts were strongly constructed, they made a foolproof prison for a flightless bird.• All penguins are flightless but are perfectly adapted to life in water and to withstanding cold.• They act like huge and flightless cuckoos, as they stroll off and take no part in parental care.• During this time, the flight feathers are all replaced simultaneously, making the bird flightless for a while.• Another noticeable bird of the shores is the flightless steamer duck.• The falcon spreads flightless wings and stalks among months of droppings. 