Definition of "hypergolic" [hypergolic]

• Of or relating to a rocket propellant consisting of fuel and an oxidizer that ignite spontaneously on contact. (adjective)
• Using such a fuel. (adjective)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The fuels are hypergolic, meaning they require no ignition source but ignite spontaneously when mixed with an oxidizer."
• "The new fuel is hypergolic, meaning that it needs no ignition source, but burns when exposed to an oxidizer."
• "I don't know how well the math works but if the propulsion needs are light enough, or if the mission module could carry some simple hypergolic fuelled trusters, but maybe you could use the "mission module" with a cheaper, LEO optimized capsule like Dragon or even Soyuz."