neˈossoptile Ornith.
[f. as prec. + πτίλον a down-feather.]
One of the soft feathers of a newly-hatched bird, as contrasted with those of a mature type (teleoptiles).
| 1893 Gadow in Newton Dict. Birds 243 Soft feathers..possessing several characters which make it advisable to distinguish them by the name of ‘Neossoptiles’. |