To move through the air by the aid of wings, as birds.To pass or move in air by the force of wind or any other impulse: as, clouds fly before the wind; a ball flies from a cannon, an arrow from a bow; the explosion made the gravel fly.To rise, spring, shoot, or be cast in air, as smoke, sparks, or other light objects.To move or pass with swiftness or alacrity; go rapidly or at full speed; rush; dart: as, to fly to the relief of a distressed friend; the ship flies before the wind; recriminations flew about.To depart suddenly or swiftly; take flight; escape; flee: as, the rogue has flown; his fortune will soon fly.To part suddenly or with violence; burst or be rent into fragments or shreds: as, the bottle flew into a thousand pieces; the sail flew in tatters.To flutter; wave or play, as a flag in the wind.To be evanescent; fade; disappear: said of colors: as, that color is sure to fly when the fabric is washed.To hunt with a falcon; hawk.To resist; set at defiance; oppose with violence; act in direct opposition to.To revolt.To evaporate or volatilize.To break out in anger, uproar, or license.To assail; abuse.Nautical, to let go suddenly: as, let fly the sheets.To cause to move through or float in the air: as, to fly carrier-pigeons; to fly a flag or a kite.To attack by the flight of a falcon or hawk; fly at.To flee from; shun; avoid as by flight; get away from: as, to fly the sight of one we hate.n. The act of flying, or passing through the air; flight.n. A state of flying: in the phrase on the fly (which see, below).n. Something having a rapid or flying motion, or some relation to such motion.n. plural In a theater, the large space above the proscenium, extending over the whole of the stage, and including the borders, border-lights, many ropes, cleats, and pulleys, the beams to which these are attached, and the fly-galleries on either side from which the borders and drop-scenes are handled.n. A piece of canvas drawn over the ridge-pole of a tent, doubling the thickness of the roof, but not in contact with it except at the ridge-pole.n. The flap or door of a tent.n. A strip of material sewed to a garment, but differing from a flounce in being drawn straight without gathering, and usually serving some purpose other than mere ornament.n. In cotton-spinning, waste cotton.n. The hinged board which covers the keys of a piano or an organ when not in usen. In popular language, a flying insect of any common kind.n. In entomology, a two-winged insect; any one of the order Diptera, and especially of the family Muscidæ: commonly used with a qualifying or specific term: as, the house-fly, Musca domestica. See the compounded words.n. A fish-hook dressed with silk, tinsel, feathers, or other material, so as to resemble a fly or other insect, and used by anglers to entice fish.n. A familiar spirit: apparently a cant term with those who pretended to deal in magic and similar impostures.n. Figuratively, an insignificant thing; a thing of no value.n. Pl. flys (flīz). A kind of quick-running carriage; a light vehicle for passengers; a hackney-coach.n. An ephemerid; a shad-fly, May-fly, or day-fly. (See also cabbage-fly, forest-fly, hand-fly, radish-fly, robber-fly, saw-fly, stretcher-fly, etc.)To convey in a fly.To travel by a fly.Knowing; wide-awake; quick to take one's meaning or intention: as, a fly young man.n. See vly.n. n. Nautical, an old-fashioned name for the compass-card.