hypergolic

From Ancient Greek ὑπέρ (hupér) + ἔργον (érgon, “work”) + -ol + -ic, after the model of German Hypergol and hypergolisch. Equivalent to hypergol + -ic.

• IPA^(key): /hʌɪpəˈɡɒlɪk/

hypergolic (not comparable)

1. (chemistry, aeronautics, of a reactant, fuel, or propellant) Igniting spontaneously upon contact with an oxidiser.
   • 2016, Pasquale M. Sforza, Theory of Aerospace Propulsion, 2nd ed., Elsevier (Butterworth-Heinemann), page 565:

     Although the LF₂-LH₂ cryogenic combination is hypergolic, the toxicity of the fuel and the products of combustion have made the use of this system impractical. In general, the commonly used hypergolic propellants are considered conventionally storable, that is, they do not need special refrigeration equipment to keep them liquid.

2. (chemistry, aeronautics, of a reaction) Involving such a hypergolic agent.
   • 1994, Stephen K. Hall, Chemical Safety in the Laboratory, CRC Press, page 65:

     The chemical reaction range of hypergolic mixtures varies from slow and barely visible to an instantaneous and highly visible explosive force.