Apterium

Origin

See aptera.

Full definition of apterium

Noun

1. (ornithology) An area of bare (featherless) skin on a bird.
• 1918, American Ornithologists' Union, The Auk, The two halves of the lower cervical tract are still separated by an apterium 4 mm. wide, as in the young bird, but contour feathers are now present on the chin and upper throat, so that they are united at their upper ends.

Antonyms

• pteryla