An immature feather, before the veins have expanded and while the shaft is full of fluid.
〔鸟〕纤羽，毛羽
Example sentencesExamples
They grew in much the same way Crixa's did, but small, white and red-brown pin feathers began to layer themselves over the bone and muscle.
Changes in the physical structure of the pin feather during growth may be the most likely explanation for the increased resistance to heat loss in both groups of birds.
On that particular afternoon I recall a lot of references to ‘pin feathers’ interspersed with colorful expletives.
He could feel the pin feathers, and the grossness of its shape.
Cockatiels are born nearly naked and pin feathers start to appear at about seven days.