Of a feather: fully developed, quilled.

Of feathers: resembling a sprig or spray; sprouting up in the manner of a shoot or sprig. Obsolete.

That rises in or forms a ruff or ruffs.

(un-, prefix1 affix 2.)

Having or furnished with a shaft or shafts. Ornithology. In combination with prefixed word: Having the shafts (of feathers) of a specified character…

Of the nature of a filoplume.