Merriam-Webster's Collegiate® Dictionary, 11th Edition
FLARE
I. noun
Etymology: origin unknown
Date: 1580
1. a fire or blaze of light used especially to signal, illuminate, or attract attention, an unsteady glaring light, solar flare ,
3. a sudden outburst (as of excitement or anger), flare-up 3,
4. a spreading outward, an area of skin flush, light resulting from reflection (as between lens surfaces) or an effect of this light (as a fogged or dense area in a photographic negative),
6. a short pass in football thrown to a back who is running toward the sideline, a weakly hit fly ball in baseball , pants that flare toward the bottom,
II. verb (flared; flaring)
Date: 1616
intransitive verb
1. to burn with an unsteady flame, to stream in the wind,
2. to shine with a sudden light , b. to become suddenly excited or angry, to break out or intensify usually suddenly or violently, to express strong emotion (as anger) , to open or spread outward , transitive verb to display conspicuously , to cause to flare , to signal with a flare or by flaring, to burn (a jet of waste gas) in the open air