Definition of: feather

(feth′ər) noun
1. One of the horny, elongated structures which form the body covering of birds and provide the flight surface for their wings. It consists of a central shaft composed of a hollow part near the body called the quill and a distal solid part, the rachis, along each side of which is a series of processes, the barbs. The barbs are provided with a fringe of smaller processes, the barbules, which in turn are equipped with barbicels, or hooklets, the whole composing the vane of the feather.
2. Something resembling a feather, as in mechanisms; a tongue, wedge, or fin.
3. Kind; class or species: birds of a feather.
4. Frame of mind; mood; spirits.
5. In rowing, the act of feathering.
6. The wake of the periscope of a submarine.
7. An irregular flaw in a gem.
8. The hairy fringe on the backs of the legs and on the tail of some dogs.
9. plural Plumage; by extension, dress or attire.
10. A fin or guide on the shaft of an arrow.
11. Anything light or trivial: A feather would upset him.
—a feather in one's cap An achievement to be proud of; a thing to one's credit.
—in full feather In full force; fully equipped.
—in high, fine, or good feather In a cheerful or confident frame of mind.
—v.t.
1. To fit with a feather, as an arrow.
2. To cover, adorn, or fringe with feathers.
3. To join by a tongue and groove.
4. In rowing, to turn (the oar blade) as it comes from the water until it is horizontal or nearly horizontal, thus offering the least resistance while reaching for a new stroke.
5. Aeron. To turn one edge of (the propeller blade) into the wind, thus minimizing drag.
—v.i.
6. To grow or become covered with feathers.
7. To move, spread, or expand like feathers.
8. To feather an oar or propeller blade.
—to feather one's nest To provide well for one's own future while acting as the agent of another. [OE fether]