A sudden and rapid fire email conversation that sparks up between 3-5 people about a given topic that results in no fewer than 21 emails on the given topic. Distinction between g-flares and other email chains, must deal with a singular topic, must occur between Gmail users (showing cascading email chain), must happen quickly and once the subject matter has been exhausted it will never be written about or spoke on again. They usually occur Friday afternoons.
In a sentence:
Kevin, Garen, Roland, Branny and I had a nice g-flare about vintage ski gear the other day, but once we covered the 1986 Bogner winter collection we were done.