A contour feather of a bird, as distinguished from a down feather or a plume.
a contour feather
an ideal, or regular, feather.
In ornithology, a feather; a plume; particularly, a contour-feather, as distinguished from a down-feather or plumule; specially, one of several big rigid feathers of this wings or tail; one of the remiges or rectrices. See feather.