—v.i. 1. to burn with an unsteady, swaying flame, as a torch or candle in the wind.
2. to blaze with a sudden burst of flame (often fol. by up): The fire flared up as the paper caught. 3. to start up or burst out in sudden, fierce activity, passion, etc. (often fol. by up or out): Tempers flared at the meeting. Violence flared up in a new section of the city. 4. to shine or glow.
5. to spread gradually outward, as the end of a trumpet, the bottom of a wide skirt, or the sides of a ship.
—v.t. 1. to cause (a candle, torch, etc.) to burn with a swaying flame.
2. to display conspicuously or ostentatiously.
3. to signal by flares of fire or light.
4. to cause (something) to spread gradually outward in form.
5. Metall.to heat (a high-zinc brass) to such a high temperature that the zinc vapors begin to burn.
6. to discharge and burn (excess gas) at a well or refinery.
7. flare out or up, to become suddenly enraged: She flares up easily.
—n. 1. a flaring or swaying flame or light, as of torches in the wind.
2. a sudden blaze or burst of flame.
3. a bright blaze of fire or light used as a signal, a means of illumination or guidance, etc.
4. a device or substance used to produce such a blaze of fire or light.
5. a sudden burst, as of zeal or of anger.
6. a gradual spread outward in form; outward curvature: the flare of a skirt. 7. something that spreads out.
8. Optics.unwanted light reaching the image plane of an optical instrument, resulting from extraneous reflections, scattering by lenses, and the like.
9. Photog.a fogged appearance given to an image by reflection within a camera lens or within the camera itself.
10. Also called solar flare.Astron.a sudden and brief brightening of the solar atmosphere in the vicinity of a sunspot that results from an explosive release of particles and radiation.
11. Football.a short pass thrown to a back who is running toward a sideline and is not beyond the line of scrimmage.
12. Television.a dark area on a picture tube caused by variations in light intensity.