WordNet sense 1 (a shape that spreads outward):

flair

WordNet sense 2 (a sudden eruption of intense high-energy radiation from the sun's surface; associated with sunspots and radio interference):

solar flare

WordNet sense 3 (a burst of light used to communicate or illuminate):

flash

WordNet sense 4 (shine with a sudden light):

flame

WordNet sense 5 (burn brightly):

burn up, blaze up, flame up

WordNet sense 6 (a short forward pass to a back who is running toward the sidelines):

flare pass

WordNet sense 7 (erupt or intensify suddenly):

erupt, irrupt, break open, burst out, flare up

WordNet sense 8 (become flared and widen, usually at one end):

flare out