In woodwork, a form of veneer decoration, also called herringbone crossbanding. Like crossbanding, it uses the grain of the wood to form a pattern. Thin strips of wood were cut diagonally against the grain, then two such strips were put together, one reversed, so that the grain made V shapes, like feathers or herringbone.
Feathering was used throughout the walnut period of English furniture, that is from about 1660 to 1730.
In pastel drawing, feathering is the addition of light parallel strokes over the coloured surface for a softening effect.
In architecture, it is a decoration applied to an arch, consisting of small alternating arcs and projecting cusps.
On a rabbit, feathering is a 'drag' (small intrusion of coloured fur) in the white fur above the eyes.
More generally of course, any ruffled effect on a surface resembling feathers, or any ornamentation by applying real feathers; and let us not forget the thing you do to someone after tarring them to punish them, nor feathering the nest in the sense of taking cuts or bribes or advantage of one's situation.