What does FLARE mean?

noun

1. a shape that spreads outward“the skirt had a wide flare”
2. a sudden burst of flame
3. a burst of light used to communicate or illuminate
4. reddening of the skin spreading outward from a focus of infection or irritation
5. a sudden recurrence or worsening of symptoms“a colitis flare”
6. a sudden eruption of intense high-energy radiation from the sun's surface; associated with sunspots and radio interference
7. am unwanted reflection in an optical system (or the fogging of an image that is caused by such a reflection)
8. a sudden outburst of emotion“she felt a flare of delight”