hy·per·gol·ic 
(hī′pər-gŏlĭk)
(hī′pər-gŏlĭk)adj.
1. Of or relating to a rocket propellant consisting of fuel and an oxidizer that ignite spontaneously on contact.
2. Using such a fuel.
[From German Hypergol, a hypergolic fluid propellant : from hyper-, extreme (from Greek huper-; see HYPER-) + Greek ergon, work; see ERG1.]
hyper·gol′ (hīpər-gôl′, -gōl′, -gŏl′) n.
hy′per·goli·cal·ly adv.