hypergolic
adjective
hy·per·gol·ic ˌhī-pər-ˈgä-lik 
1
: igniting upon contact of components without external aid (such as a spark)
2
: of, relating to, or using hypergolic fuel
hypergolically
ˌhī-pər-ˈgä-li-k(ə-)lē
adverb 
Example Sentences
Recent Examples on the Web Lasting about 2 minutes and 40 seconds, the video shows instances where Pythom employees appear to be handling the Eiger rocket and its hypergolic propellants with less than industry-standard care. 
Eric Berger, Ars Technica, 15 Apr. 2022 Jiuquan currently only handles launches of older hypergolic Long March rockets and solid rockets, necessitating a new complex. Eric Berger, Ars Technica, 21 Jan. 2022 Unlike its predecessor, the Titan II used hypergolic propellant, with fuel and oxidizer stored in the missile—at room temperature—and mixed to launch almost instantaneously. Vince Guerrieri, Popular Mechanics, 18 Sep. 2020
Eric Berger, Ars Technica, 15 Apr. 2022 Jiuquan currently only handles launches of older hypergolic Long March rockets and solid rockets, necessitating a new complex. Eric Berger, Ars Technica, 21 Jan. 2022 Unlike its predecessor, the Titan II used hypergolic propellant, with fuel and oxidizer stored in the missile—at room temperature—and mixed to launch almost instantaneously. Vince Guerrieri, Popular Mechanics, 18 Sep. 2020 Word History
Etymology
German Hypergol a hypergolic fuel, probably from hyper- + erg- + -ol (hydrocarbon)
First Known Use
1947, in the meaning defined at sense 1